A good example of what I mean is actually German mirror. Why do people go dopps in German mirror on TP maps? Dopps are not considered a particularly good unit (at least they are very expensive and situational). So why does the other German player not just FF against it? Primarily because it is too risky, you might be belled, raided and/or your buildings razed.
Lots of civs have units that are actually better than dopps (musks). So why not use those to rush or at least pressure? Sure, they have less siege than dopps, but they have more range, beat xbows situational and can also raid vills more easily.
If Germany wouldn't freely/safely/successfully (semi) FF vs dopps, why would they vs musks?
Also note that the doppel meta is fairly new, people used to Uhlan semi FF in mirror. Things change and evolve, so maybe some strategies are being overlooked.
: I'm not saying anyone is dumb, but as you know yourself, meta changes even without (significant) balance changes. Indian sepoys are arguably used more at the top level despite being nerfed. Aztec FI was discovered without any changes many years after game release. Same with memefire.
Lots of people use and find new strategies all the time. Many people play differently. Originally, people would never use walls, now they are used despite being nerfed, even at the top level.
Point is: meta is not set in stone and often more based on preferences than anything else.
As far as rushing Germany is concerned: it's impossible to describe every possible situation and discuss it. The point is though, as you agree, a full rush can kill a German ff or semi. Obviously Germany can adapt against that - - but so can the rusher. If Germany defends, they either go 8 bows or 700w first, already slowing them down. If they go 3 SW, they remain very vulnerable.
Just because the rusher made one or two raxes that doesn't mean he can't then manor boom or send 4 cdb or grab TPs. Also, as you know, Germany loses a prolonged age2 fight VS almost every civ.
I just feel it is not all so cut and clear. A semi FF vs Germany might seem like a nice and safe option because it isn't as all in, but maybe the winning chances would actually be better if you forced an age2 engagement. And yes, WWs can kite, but 3 WWs don't beat high numbers of musks (or you get belled /hunting vills killed).
I actually haven't seen that many games in which Germany was under heavy age2 pressure. Most people instead seem to just go into an FF war and/or boom/turtle (depending on civ) and then get overwhelmed. In some games in which people did pressure and annoy Germany early on (eg Turk (I think?) as Japan vs tabben's Germany he at least killed 2 TPs etc and later on mostly lost a fairly even game due to micro/bad engagements; or the tournament game where tabben lost VS brits).
: the fb should be up before the 2 uhlans arrive, right? Or do you mean that your base gets raided? VS the latter you can also protect yourself by making 50w worth of walls around your hunts and mine which on EP should be close to your TC anyway.