Many dancers exhibit incredible flexibility, strength and control; the same can be said of gymnasts. Now, gymnasts in general are going to be stronger with all the tumbling and so forth, but generally speaking does a Prima Ballerina exercise better body control?
Depends on how you look at it. A ballerina probably has less wavering in their movements, so in that sense you could say that she’s exerting more control. But, she’s not in as awkward and difficult of positions as a gymnast would be. For the gymnast, just landing in something akin to grace is already quite the feat, let alone doing it without any excess wobble.
Overall, I’d say that so long a we’re talking about choreography, it’s all the same. The amount of body control going into it is roughly the same because the goal is the same. Just, what can be accomplished with one is less than with the other.