Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

If forgeworlds are run by the mechanicum, is it reasonable to assume that they can have any imperial based vehicle/aircraft within their own army lists?

Imperium loyalists can all roll together pretty much. I'd say you can definitely have any Imperial vehicle in their army list, especially since no official rules exist.

As above. Also, remember that the Ad Mech have all kinds of crazy tech around, so even if they aren't using certain types of tank for whatever reason, there will be something that can counts-as pretty easily. Like the Inquisition, Ad Mech make great counts-as armies.

The Mechanicum has access to literally every Imperial Vehicle, and their versions are better than everyone else's. That's kind of the perk of being the Mechanicum.