Hi Tom,
Yes it's legal. I'm sure EASA would like to make it not so, but they had to recognise that there are many variants out there for which there is no sim. So, for example, if your airline has A321s, you still use a 320 sim as there are no 321 sims. Interestingly, in that case there is very little difference in the flight deck but I understand that the landing is quite different; compared to the Globals where the handling is identical but the flight deck layout is quite different.
See you soon!