Transported units selction - workaround?

Air transports. Normally set to carry anything that is not marked as non-transportable. There is an exception list where you designate that it only be able to transport ONE unit type, even if normally non-transportable.

Here's what i'm doing. I'm adding light and heavy air transports to a map. Light transports are easy, I won't mess with what they can transport and they can carry all the varieties of ground troops/militia/etc. Heavy transports I want to be able to move armor.

So far I only see 2 ways of making this happen, and neither way will work for what I want to do. #1 - I only have 1 type of tank, mark it as non-transportable so the light transport can't move it, and add tank to the heavy transport in the one transport slot. #2 - I keep my varying tanks by nation, but only allow heavy transports of THAT nation be set to transport tanks of THAT nation. If England takes over Germany, their heavy transports can't move german leopard tanks.

Can anyone think of a workaround for this? It's getting in the way of what I want to do with some of naval units as well.

Thank you.

I might have it. Since I didn't plan on making unique infantry to every damn country in the world and just used 'infantry', I can make 'infantry' non-transportable. Then assign them to the light air transports and a common transport ship. Then have the heavy air transports and RO-RO transport ships still without any transport restrictions so they can move all brands of tanks and mobile AA/SAM.

Militia... i'll just have the transportable only by dirt cheap common air service carriers & civilian trucks, or by nothing at all.

Anti-tank... i'll lump them in with tanks and just say they have 'heavy equipment and multiple reloads giving them the equivalent weight/space as an armored unit'. Or maybe take them out completely.