If you complete a reasonable amount of industrial focuses (on either side of the Agrarian vs Industrial split with at least two of the follow-ups granting MILs) and improve relations with all relevant powers that can grant you free factories (especially if you go Agrarian over Industrial) you can have a strong enough economy to outfit your initial 13 divisions and a few port garrison battalions for your homeland. In addition, you should utilise your fleet to engage any landing parties; I tend to put my submarines and my minelayers in two different scout flotillas and use the remaining ships as a strike force based in Crete.
This gives you the following scenarios:
- The Great Powers agree to carve up Turkey, and both Britain and France join the war against it. In this scenario, the war will be largely effortless.
- The Great Powers agree to carve up Turkey, but only France or Britain joins the war against it. Here the war will be a little more challenging but you can count on strong Allied participation regardless.
- The Great Powers refuse to carve up Turkey. This leaves you one-on-one against Turkey (and Romania) but your fleet should be a powerful deterrent against naval landings in your mainland, while you can concentrate most or all of your starting divisions in Thrace.
- In all cases you can have your war with Turkey finished or about to finish in 1939, but not necessarily Romania.
First and foremost, it is imperative that you take the correct advisors for your military; you want to hire the speed (
Pangalos Plastiras, I believe) and infantry (Zervas, I believe) experts. This will improve your army's combat effectiveness as much as possible, in addition to increasing its speed to assist with exploitation of breakthroughs as well as flanking (this is especially nice if you maintain your cavalry division).
If you produce artillery, support equipment, guns and anti-air (with 1 factory in each, except guns where you should aim for as close to 5 as possible) you can outfit your divisions to 7/2 mountaineers and infantry (with support engineers, anti-air and recon) and add support artillery and perhaps anti-air to your cavalry division (if you care). This will allow you to easily split the Turkish frontline in Eastern Thrace in two and seize Istanbul before they can garrison it; then you can clean up the area before crossing over to Anatolia.
The push will be easier if France and/or Britain join you (especially if the former does, thanks to its shared land border with Turkey in Syria) but if it ends up as a one-on-one (because, for instance, you're going for a Byzantine run and/or the Allies cucked you over) you can still win. Your navy should easily handle the Turkish and Romanian fleets, as well as landing forces; you should easily have air superiority in the Balkans for your initial push, but you might have to sacrifice either or both of Lesbos and Chios, the two islands just off the Asia Minor coast. However, it is good if you can hold one or both, just for the sake of distracting a reasonable amount of Turkish divisions trying to contain and/or assault them.
Once your land forces have crossed into the Asia Minor, focus on expanding your frontline and destroying any remaining Turkish units. Once Ankara falls, the capital will more than likely move to Trabzon; you can then cut it off from Mediterranean ports and mop up the now-encircled and outnumbered Turkish units in West and South Anatolia, while mopping up towards Trabzon itself. Your cavalry division will be invaluable thanks to its speed, especially to exploit breakthroughs (such as in Eastern Thrace) and seizing valuable ports in the mop-up stages in advance of infantry divisions.
Once Turkey capitulates you will receive your peace treaty. With sufficient participation you will be able to expand your domain over more Turkish territory where possible, before the Anglo-French do, but with some luck you can even set up a supervised state and claim the remaining Turkish territory for it. If you did this solo, simply annex all of Turkey and form Byzantium (if that was your goal).
The last part of the war is mopping up Romania. Depending on your plans, time might be of the essence, especially if you want to join the Axis (but be warned that if Bulgaria also joins at any stage, a current bug will have Germany transfer Central Macedonia and Thrace, if not more terrain, from you to Bulgaria unilaterally). This last part is easier if you have allies in the war; if not, it becomes trickier. You will need to organise a naval invasion, successfully land in Romania, and push to capitulate it before Italy declares war on you, as your homeland will be mostly exposed. There is a decent chance that Romania joins the Axis before it capitulates however, making you the reason for World War 2 rather than Germany invading Czechoslovakia or Poland.
After this point you can concentrate on expanding your military, or simply improving its quality and using it as crack troops to push certain Allied objectives (such as landing in Sicily or South Italy en masse, help defend Yugoslavia from the Axis invasion, etc). During the war, you can and should focus on going down the Hellenic Army focus paths; push deep enough and your troops will be nearly uncontested in mountainous terrain, which you can find plenty in the Balkans, Anatolia, and even Italy.
A special note must be made for the Generals and Field Marshals you have access to. By now you should have access to both Republican and Monarchist leaders; you start with Field Marshal Papagos and several capable generals such as Pangalos, Plastiras and Zervas. Several will even have the Mountaineer trait unlocked. You can make two army groups, one defensive and one offensive; the former can utilise Papagos, who comes with great defensive traits and stats, while the latter can be led by a promoted
Pangalos Plastiras, who has access to great traits and stats for attacking instead. If you end up going fascist, you can join up forces with the Communists for access to even more military leaders, such as Velouchiotis.
Finally, your fleet doesn't need to be ignored. Between the game's start and your Greco-Turkish War, you can produce between 2 and 4 minelayer destroyers; there is little reason not to do so. For later on you can hire the Coastal Defence Fleet designer, refit your battleships (a certain focus is required for this) and even produce some new destroyer and cruiser designs to augment your fleet (which will be cheaper to do so, and thus can be handled by your relatively weak industry a lot better; the reduced range won't be an issue in the Mediterranean at all).
Bonus! If you want to use some accurate Greek names for your army groups and armies, consider the following:
- Stratia refers to an Army; for example, "1i Stratia" would be the 1st Army and "Stratia Makedonias" would be the Army of Macedonia. IRL this is used for 'army group' level organisation by game standards.
- Soma (Stratou) refers to a(n Army) Corps; for example, "1o Soma Stratou" or "1o Soma" would be the 1st Corps and "Soma Kritis" would be the Corps of Crete. This would best fit your armies (and is accurate if you have ~6-7 divisions in each, roughly speaking).
- Omada Stration refers to an Army Group; for example, "1i Omada Stration" would be the 1st Army Group, and "Omada Stration Papagos" would be the Army Group Papagos. This isn't accurate by IRL standards however, as Greece has a small military and historically only fields the administrative equivalent of about 2 or 3 field armies.
- Stolos means Fleet, and Stoliskos means Flotilla. The former refers to the entire navy; that would be the beginning "Vasilikon Naftikon" equivalent (meaning Royal Navy). For flotillas, there is stuff such as "Stoliskos Ypovrychion" (Submarine Flotilla) and you can use terms like "Stoliskos Anagnorisis" (Reconaissance Flotilla) or "Stoliskos Katadromikon" (Cruiser Flotlilla) if you'd rather not number them. Instead, if you number them, the correct form would be using the suffix -os for the number (eg 1os for First, 21os for 21st, etc; followed by Stolos or Stoliskos).
Sorry for the long post, I hope you found it informative!