I don't really see the problem with Devolved = rookie -> Human and Beast = Adult -> Fusion = Ultimate -> Transcendant = Mega -> Susanoomon = Lv. 7
The problem is basically all of the official media describing Hybrids. let's start at the bottom:
Strabimon's profile states that Wolfmon's power was halved. It also states that its power surpasses that of "typical" adult level Digimon. The same is stated in Flamon's profile This means Wolfmon'a and Agnimon's full power is
already beyond that of most adult Digimon, and I would argue that this would reasonably extend to the rest of the Human Hybrids as well.
And there is nothing inconsistent about that, we have
seen human spirits defeat Perfects. We have seen them evolve from Adult Digimon as well as Child Digimon. But Beast forms have, besides clearly outmatching the Human forms in the anime, been shown to evolve from Adults or even Perfects, but never directly from Child Digimon (until the Pendulum Z), putting them consistently at least at Perfect class.
The classification of the Fusion spirits as Perfects instead of Ultimates is a clear downgrade because having reunited both spirits, their power should be equal to that of the ancient Warriors (the profiles confirm this, stating in each case that they inherited "all the might" of their ancient counterparts) the ancient warriors, of course being Ultimates, not Perfects and not even especially weak Ultimates at that (AncientGreymon is even said to have power
surpassing "current Ultimates").
The Transcendent forms were capable of taking on Royal Knights, who are often established to be on the higher tier of Ultimates, both in Frontier itself and the following media like Savers where Burst Modes were needed to keep up with them.
Again, I don't think any of this is inconsistent. There wasn't anything illogical going on. The inclusion of the transcendental forms was strange back in 2002 when anything beyond ultimate was usually reserved for the very final conflicts and not something that happened after two thirds of the story. But that was back then.
The irony is that the franchise is in a place now where we have quite a significant number of number of Digimon with forms beyond Ultimate, so anything from Fusion Hybrids up being Ultimates wouldn't really be a serious balance concern when including them in games and such.
So it's strange that
right now they decide to downgrade them for the card game.
