if they are the same size it goes either way. Topo is physically stronger based on his ability to rip submarines in half but Karaqan has the breath attack and can hit from range.
Topo also doesn't have a durability feat either so...
Actually I lied. Topo wins.
I look at my scans again and Topo got shot with a torpedo and it didn't do anything. Torpedos are basically like missiles which the Karaqan can take too and his breath has the same power more or less by destroying the jets.
Topo should win based on higher raw strength even if they are the same size.