. . .As an aside, I wonder what Bashir might have done had he been forced to fight. His genetic enhancements might have helped him defeat Jem'Hadar, but would he have risked revealing his secret just to stay alive? An interesting idea could have been to have him suddenly overpower a Jem'Hadar solilder- perhaps to save Garak- and claim that his adrenaline took over. As his secret was revealed in the following episode, it would have been a nice hint at what was to come. . .
But not even Siddig knew about the genetic enhancements when they were filming those earlier episodes. He learned it the next week when he first read "Dr. Bashir I Presume?" Surprise, you're suddenly not who you thought you were. And they did it to him twice in a single month. It's almost as if the writers knew
we'd be trying to retcon explanations for all of Bashir's earlier behavior for the next 20 years.
On those impersonated prisoners, I suppose the Founders might recognize their value when it came to forcing their enemies to surrender (Yield, or we'll kill your king). And perhaps they're also studied so other impostors can learn their speech and behavior patterns.