Almost necro, but close enough. I need to let this one out of my head
First thing first, since physical strengths are equalized, Doramed should be the size of a fairly large building. Now the thing is Blake and most RWBY characters have experience fighting larger foes, while I don't recall good showings of Doramed fighting those much smaller than him. Also, unless I'm wrong, most people would look at a bigger opponent and think of attacking from the inside by hopping into the big foe's openings like mouth and stuff. Doramed has a big mouth, so it's likely Blake's first option is to attack it. That said, Doramed is quick to recognise the patterns and weakness of his opponent, so that shouldn't be an overwhelming disadvantage for him. Shapeshifting into something without those obvious weak spots is also something Doramed would employ.
Also, due to his increased size, most of his attacks that he starts in-character (fire, lightning, wind, flying swords and/ or hammers) have a pretty big AoE. They can deal with Blake and her clones, and probably the dust ammo she throws at him as well. I should also mention that while their physical strengths are equalized, Doramed's magics mentioned above hurt him a lot, so they should hurt plenty to Blake.
Another thing, unless Blake KO and kills Doramed quickly, hurting him will only make him angrier, meaning he will get even bigger to the point where Blake's attacks become insignificant.
So overall Doramed has the advantages of attacks with big AoE and slightly stronger AP than Blake's dura to counter Blake's smaller and more nimble size, clones, and probably dust. However, Blake is not helpless, as if she attacks before Doramed could with status effect dust and Blade Beam, she can gain the advantage of ganging up on a stunned/ frozen/ blinded Doramed. BUT unless she uses that advantage quickly and KO or kill Doramed, Doramed would get angry from the pain and grows larger, amping himself further to the point of AP stomping Blake.
TLDR; Doramed has my vote
