That's true, though who knows how it will all end. However, I wouldn't particularly mind even if not all got their super fight before this arc is over, because it might actually make more sense, even if it fought against the shounen traditions. Caesar is a scientist and the fact he had even this many troops (as pitiful as they are against strong opponents) was pretty much an accident. It wouldn't make too much sense if he had a whole host of uber fighters under his commands. Vergo having some with him might be plausible, but if he sneaked in without anybody noticing, he couldn't have brought a too large company. This might not turn out to be a real, simple fighting arc. The previous one wasn't either, with Luffy being the only one with a tough opponent (as long as they were underwater).