RTF is a global modification that replaces all towns in the game.

There are excellent models in NCF format; I don't know what can be changed here, as everything already looks great.

The left one is too small; it would be better to base it on the Herald, like the other two. And the ones based on the Herald already look like a base model and an upgrade; all that's left is to come up with an alternate upgrade.
P.S.: The Reaper turned out great – I take my hat off to you!