That should have been word, of course! Maybe my predictive text making its own qualitative judgement :-)

It really doesn't matter. Everywhere else in the English speaking world, Lego is a collective noun. In America they say legos, which sounds stupid and childish to everyone else. But it doesn't to them. So live and let live. Laugh if you like, but it's their common usage so it's not wrong in an American context. I like American English anyway. Try winningest. You'd never use it but it brings me joy that this weird exists somewhere.