Well, they wouldn't need many, given that "the rest of Europe" is weak in their will to fight for themselves.

(I suppose they can just give up their lands, like France did in WWII.

Does anyone remember those interviews with Polish and British people in the streets back in 2023 or smth? The former said they'd flee from the country and wouldn't fight; the latter said they'd expect their government to do smth to prevent fighting rather than sending people to protect the country from invasion.

And what about the fact rus missiles reached Romania and Poland several times already, but both "closed their eyes" on that in order to not escalate because it would involve NATO in that "conflict between two brotherly nations"?

The rest of Europe (well, maybe except for Baltic countries) still believes that negotiations with russia are possible. They ask Ukraine for that and are okay with Ukraine to give up its territory and people. I think we already saw how such negotiations and agreements worked with Hitler back in 1938, no? Check the Munich Agreement, as a minimum.)