@ Histidine: I will not lie, I reloaded many times. I see it much like continuing on Ghosts & Goblins (or Castlevania or Ninja Gaiden) on the NES. Also, the blobbing is partially due to me evading previous response fleets after conquering Volturn, Curor, and Umbra. In case of Umbra, I conquered it from pirates, then the Sindrians took it from me, and I had to invade Umbra again to reclaim it. I probably would have fewer blobs had I finished off the response fleets from those planets instead of evading them. By evading them, I had to deal with response fleets and patrols from every planet almost simultaneously, and because of that generous conquest mission, I could not take my time.
Most times, I can start an invasion, break off, lure the response fleet away, return to invade, then capture the planet without a fight. It usually works, but in case of Sindria being the last to invade, there were simply too many fleets everywhere to cut me off. I could not afford to buy and outfit every ship personally. For Sindria, I simply rented fleets. They are worth 120k a pop, but that is cheaper than owning a single capital, let alone a whole fleet. And those rented fleets were torn apart, but it saved my ships and tied up a few leftover response fleets.
P.S. Maybe it was Tri-Tachyon that took over Umbra. I do not remember for sure, but it does not matter. Either way, it bought the Sindrians time to get a bit stronger.