Historical choices are often dumb choices...
I've never liked the scripting function - a dead yamamoto when I'm *not* at war with the US (or when I am beating the crap out of them) always pisses me off.
What *needs* to exist is for the game engine to simulate the actual effects based on an overal game condition - not a specific trigger.
Right now anschluss (sp) happens right on schedule - wether germany is planning on being a warmonger or not (except if you are already at war... see what I mean about stupid triggers) how anschluss should work is that IF germany 'threatens' Austria (builds up a pile of troops on the border) and IF Austria is sufficiently 'pro-german/fascist' and IF germany 'demands' anschluss, then maybe you get an anschluss event (with the likelyhood of Austria accepting being tied directly to how much they like you as well as to how big a stick you are threatening htem with).
There is no reason that germany shouldn't be able to say to switzerland 'listen, buddies, either you join us, or you freaking die' why can't we have a 'swiss anschluss' or hungarian?
Something like this should be fairly doable to make happen.
Look at the following factors:
How closely are the two countries aligned (IE - ideology)
Has one country 'demanded' territory/annexation?
How much 'force' is being projected against the country under threat (how big are their relative armies, how much of that army is arranged on the border)
How good is the national unity of the county 'under threat' (if the swiss are nationalistic enough, they will tell der fuhrer to fly a kite)
How much 'support' does the country under threat have (Poland + the allies is more likely to stand up to germany rather than Poland all by themselves)
Maybe factor in belligerance into the equation? Use it as a modifier that amplifies both the effect that the difference in army size plays (a big army in the hands of a guy willing to use it is scary) AND into the effect of national unity (a very unified country may be much, much, more willing to go to war against a more aggressive nation) - this way it would become a much bigger gamble for the demanding power that was very aggressive.
Finally, build in realistic consequences to the whole process - IE, if the country under threat rejects your demands, it isn't instant war, but rather a significant 'dump' to your internation prestige, national unity, and bad for your belligerance, too - this will keep it from being a 'freebie' way to maybe get an entire country for free.
By doing that, you can set up the preconditions so that germany can 'demand' territorial concessions out of whoever they want - whether they get what they ask for is essentially dependent on the relative conditions of the two countries AT THAT POINT! Meaning you can get an austrian anschluss whenever you want (maybe).
The final thing I would say, is that you would/should need SIGNIFICANT levels of idealogical similarity, a very credible threat (enough force VISIBLE, on the border to annihilate the entire enemy army), and probably fairly crappy national unity for this to succeed.
If you come up with an accurate way to simulate these things, you can get away with the worst part of scripting - that is, inappropriate scripts firing.
Include some level of power-hungriness into all the countries (essentially how bad they want to take over their enemies - this of course could change over time depending on how the political structure of that country changes). If a country is 'power hungry' it should look at its neighbors, and try to determine who it can intimidate into joining it - and to pursue this strategy against its neighbors.
In this manner, if you set up Austria with a heavily fascist governement, and poor national unity and Germany with a fascist government and a powerful 'power hungry' value - the AI should naturally pursue annexation of austria (or invasion if annexation fails). Once austria falls...the czechs would start to look attracitive (now germany has a bigger border with them, allowing them to build up a scarier force on the border). Eventually this would lead to Poland 'Danzig or war'
IMHO - I would ALSO set up the 'territorial demand' to be effectively unlimited IF IT SUCCEEDS - once it fails, I would take the 'demand' option off the board for a LONG time. This of course leads to the question of how much you demand at a time.
You can simulate 'surprise' the same way.
Figure in the relative positions of the two militaries, their idealogies & alliances, and the actual positions of the troops.
This could be simulated by giving a Malus to the troops of ANY country that is attacked 'unaware' - ways to NOT be unaware would be having good sigint relative to whoever DOWs you, having your troops on the border, having your ships at sea (I like the idea of having your ships at sea contribute to the overall 'readiness' state of your military -it would give the major naval powers a 'reason' to spend oil and effort when essentially nothing else is going on - the idea is that even if you don't have a huge navy, maintaining a naval patrol indicates tha tyou don't want to be caught flat footed - sort of an institutional attitude against surpise)
To simulate this - think of Barbarossa.
Russia has crappy sigint, and is maintaining a poor state of military readiness on the border (that is, germany has piled up a significant amount of troops on the border without a russian response), and the red fleet is sitting in port.
Germany launches a 'surprise' attack, which because Russia is unprepared for, Russia suffers an org/surprise hit for some set period of time.
Now if Germany telegraphed their intentions TOO much (piled up huge forces on the border too early) and the russians moved heavy troops into place to face them, you should argue that high command was AWARE of the risk, and had prepared them for the prospect -meaning no surprise factor.
Anyways, that's my thoughts on the matter
-DOc