Honestly, the whole searching for a cure premise is stupid. You don't randomly fly around to planets of the week and hope to stumble across a cure to an engineered plague. You go after the guys who made it. The chances of stumbling across something useful on a random planet of the week are so low you're better off buying lottery tickets. Instead, hit Drakh research stations. Capture their scientists.
If you're going to keep the plague premise, at least drop the planet of the week bullshit and make it about raids against Drakh holdings.
You do realize they weren't really just going to random planets right? They were being fed information by Alliance members and the Rangers, and the planets they were visiting had been selected as possibilities of previously being hit with the Virus
Why would anybody think that the Excalibur's mission was the only angle being pursued to find a cure? Of course
there was research being done all over the place. Of course
there were military people involved looking to capture Drakh for interrogation. But you also have to remember that while the audience knew where the Drakh were based (Centauri Prime), neither Earth or the Alliance had that information.
And the whole searching for a cure thing was to make TNT happy, anyway. See what JMS had to deal with?