Just went through a playthrough with the idea of getting north america unified. However after researching the quite expensive tech to unify canada and the USA and merging the two nations, I wasn't expecting my 6.2 mil tech USA to drop in military tech just because I absorbed a default leveled canada (with the USA having 4 armies and canada 0 armies at the time). While I love the idea that upon unification, all the fancy robotics tech on my armies just stopped working, with sensors dropping off my tanks and AI drones falling out of the sky as the unification documents get signed, it doesn't make any sense. More to that though, why would I then bother researching the 35k tech to unify the rest of north america, if that is just going to further kneecap the countries stats?
TLDR; MIL tech shouldn't just be some simple average on unification
Suggested solutions (I prefer 1 more):
1: mil tech could take the higher value of the two nations, but individual armies only slowly catch up to the unified MIL tech (and need to be stationed at home to do so)
2: mil tech could become a weighted average of the mil techs of the two nations (weighted by the number of armies of each nation)
As an aside, a screen explaining the effects upon a nation of unification would be a nice place to show the new stats of the nation after unification. This would be a nice place for a hover-overs as well to explain why certain values will move in certain directions, for example mil tech.