He nuked Edo Japan with his Dark Matter, which I believe is city level or higher. And that was done casually, mind you. In terms of raw power, without Truth, I'd say the Earl takes it.(he should also take speed, unless I'm mistaken, as I'm pretty sure DGM just has better speed feats than FMA, reaching well into the hypersonic range, but maybe someone can correct me on that, as I don't really recall anything from the FMA series that's all that impressive speed-wise.)
In round two, it goes even worse for FMA, as none of the homunculi or alchemists, sans maybe Pride, due to his nature, have a resistance against the kind of poison that Akuma have, which literally causes disintegration shortly after contact with flesh(this includes with fumes emitted from level 1's missile attacks), with the only thing known to purge it, for the most part, being Innocence, the power used by Exorcists, due to it being the direct counterpart and opposite of the Akuma's main power source of Dark Matter.
Now, I'm not going to go NLF and say that the alchemists and homunculi can't even destroy any of the Akuma, on account of them lacking Innocence, however, close combat would be a no-go, as any touch at all with an Akuma emitting even the slightest bit of Dark Matter, will end whoever destroys any of them, and there'd be a lot.(The Earl had so many in reserve, at one point, that a horde of them literally appeared as a huge black cloud over the horizon of a passing ship of exorcists. And this is ignoring how he can straight up fuse them into gigantic monster-Akuma with but a mental command, which wield much more destructive potential than said Akuma individually(and can also lead to the birth of a level 4, even when killed, if I'm not mistaken. and a level 4 is comfortably above Allen and Kanda combined, early in the series, who produced a town level feat with their combined attack, IIRC))
This is also not going into the unique hax abilities that level 2 and 3 Akuma have shown, as they don't really matter, and are kinda overkill. Dark Matter poison alone is enough to basically be a Kryptonite for the bulk of FMA, including most of the homunculi, though I suppose one could argue for their regenerative factor keeping them going for a while longer, but against the onslaught of Akuma, especially when shit like the level 3s and 4s are unleashed, who should also be faster than any of the homunculi, given they should reach well above supersonic territory, they'll be taken out eventually.
So, yeah, without Truth, Father and FMA are kinda boned, hard-core, in both rounds.