Yes they are crappola in game, especially late game and worse under the penalties of Hard and Very Hard settings. This someway is historically realistic unfortunately, but then there are a few game tweaks that seem to exacerbate their tendencies...
All of these countries were lacking heavy artillery and modern aircraft after '41 which a supply of a few ME-109s was no where near addressing particularly late war and then their obsolete tanks was another plain altogether.
OTOH just how bad their equipment was is a bit more hit and miss, they weren't that bad off with general basic equipment mostly, but often they simply lacked enough of a ratio of or were completely without the key and important categories.
All Axis Balkan countries started with the WWI basics with pistols, grenades, bayonets and rifles, light (low velocity 75mm type) field guns and were all increasing their light field howitzers - mostly Skoda 100mm, a modest few 150mm heavies and very few 200mm+ really heavy pieces too, but at lower ratios for their armies the higher you go of the heavier higher calibers and of longer barrels for range, if they had them. Those Skoda 100mm were actually pretty good, similar to German leFH 105mm in range (until mid-war) and weight of shell and had the barrel length of the US 105mm howitzer throughout WWII, but even with that they didn't have enough of them and their place was still being filled by too many WWI 75mm light field guns. The Romanians only had half the number of these in their Divisions compared to a German, 16 to 36 and way fewer than American, 16 to 54!
Obviously in the air and for their armour they all were hopelessly out dated or under equipped with much modern aircraft and no real tanks from 1941 after the older Soviet mass stock had been eliminated and became replaced steadily from '42 onwards increasingly with many more much better varieties.
All these countries addressed their short comings in terms of modern automatic weapons during the war, Hungary copied an excellent Austrian SMG mid war while Romania received a few Italian Baretta M-38s, the best SMG of the '30s and then developed their own similar to an MP-40 to make enough numbers. Most of these countries used the Czech ZV26/30 light machine-gun that the Bren gun was a near exact copy of, while the Hungarians also used a copy of the Austrian L30 which the MG-34 was based upon. Again for their HMG most employed the Czech ZV-37 which was a very good 'medium weight' modern HMG similar to the MG-34 on a tripod mount and fired the very same round although some countries still had to employ their WWI Schwarlose HMGs, but these were equal to the Maxims the Russians mostly used opposite them.
One area they all were weak in was heavy anti-tank guns and remained lacking in to the end of the war except Romania, interestingly most were reasonable provided with light anti-tank guns and rifles for early Barbarossa but that didn't help much against T-34s or KVs.
The biggest killer in game is these countries Officer Ratio - that approximately 25% limit of effectiveness of Romanian Divisions in the late war scenarios is because of the terribly low Officer Ratio and another game issue is the problem with the AI not promoting/demoting Generals and that it doesn't change its hierarchy to improve things and maximize the benefits of HQs and traits. So despite how well or not PI has these countries armies represented or not, especially over time since the AI fails to properly pursue a concentrated research program, there are a lot of game features that the AI can't handle either to make these minors worthwhile accepting as Germany to have them fight.
