[Morkai]

from what I know and understand it is completely legal to have one team as two models on seperate bases. I would suggest you still keep a base contact between them just for appearances sake but It's not necessary. In fact, some of the metal guard regiments come with two-model heavy weapon teams (namely the steel legion missile launcher).

I actually plan on doing something like this for most of my heav weapons so I see no reason it would be dissalowed. Mind you there may be something I don't know so what for further answers before modelling.