Could we get a Unicron combiner? Not meant to represent Unicron himself, just characters touched by Unicron whose combined form is dominated by those influences.
Motormaster has the horns on the head, and some versions of Nemesis Prime are Optimii from other universes tortured or are just aspects of Unicron himself.
Sideways from Groove seems doable.
Bludgeon from Brawl is mostly doable, and he was a minion in DW Armada, the War Within II, and the recent GI Joe vs. the Transformers comics.
With new wings, nosecone and head, one of the Aerialbots might make a passable Universe/Armada Ramjet.
There was a very adequate Armada Thrust from Combiner Wars Skydive.
I would be bothered by planes the size of motorcycles, but other than that...