As said the numbers aren't as important as they normally would be when diluted by 20 different chains of command/supply/etc, a 2:1 advantage is not enough to guarantee victory with that handicap. The training varies from state to state, some EU members train their air crews more than Russia does, some don't.
The combined EU air forces have 49 5th gen aircraft (NB: Delivered, number actually in service may be lower) compared to Russia's 12, however that is an almost negligible amount when discussing a hypothetical air war involving close to 2500 planes. Especially when considering that Russia has more gen 4++ planes than any other nation, and that a 5th gen plane is essentially just a 4++ gen with better stealth. Stealth being far less useful when operating over/near the territory of an enemy with cutting edge radar/SAM systems than it is when bombing mud huts (which is all we've ever seen the F-35 do).
Only a handful of EU members have attended red flag and hardly any were there at the same year. Only a handful of EU air forces have worked together in previous conflicts, there were four involved in Iraq and three involved in Afghanistan (and of those only two were involved in both). There were nine EU member states involved in the Libyan civil war, which considering we won that war from the air without even committing ground forces would normally be good when referencing a possible air war in support of Ukraine, however in Libya the EU air forces ran out of supplies and had to be saved by the USA. The problem with using that tactic over Ukraine is that unlike the planes the UK/France/etc sent to Libya most of the EU planes aren't compatible with the munitions the US would be using.
I'm telling you it would not be anywhere near as easy as you think for the combined EU air forces to win an air war over hostile SAMs against a single unified air force even with a 2:1 advantage.
I think you really need to look at inter NATO/EU air forces, also you do realise the vast majority of aircraft are American so not sure where this munitions incompatibility comes from?
F16/f18/typhoon/f35/Rafael/grippen? What struggles?
What weapons will they struggle to arm?
The whole of NATO and it's command structure or any western military operation is multi nation nowadays, usually with American CC
Red flag and numerous exercises are held every single year, they also swap pilots/ground crews etc.
We have just had Swiss f-18s over here, plus the obvious American presence,plus French and German.
The only thing Russia has is it's much vaunted s-500s and whispers say isreali f/35s bypassed them, plus not to mention they are sat on the ground.
You need to look up your numbers again with regards to them numbers... Russia has not used or proven thier very few stealth aircraft are any good, unlike the western counterparts.
They have how many actually combat ready again!?
300 roughly alone typhoons are in the EU, su-35 the Russian equivalent fighter is under 100 in number, so not sure what aircraft you think are equal to typhoon/gripen/Rafael in any air to air role?
