Just thinking about the topic, we know there is massive anit-Davion fear and persecution syndrome in the TC. Furthermore, with the limited communications going on during the Jihad due to whiteout, HPG destruction, etc etc, I can see how even the highest officials in the TC might not know all of the terrible planet wide atrocities that had occurred up to the mid 70's. The obvious thought is that House Davion is going for the throat, and finishing what the Urukhai started back in 66.
Two problems here for me, is that government officials and the intelligentsia in the TC should have thought two things.
1. Strange that WoB offers us a Quixote class cruiser exactly at the time when we want to avenge ourselves on a foreign force also in open warfare with Blake forces. It is too easy, too perfect.
2. History. This is something that any citizen could have noted, not just government officials or the intelligentsia.
3rd Succession War: No nuclear weapons used by the AFFS.
4th Succession War: No nuclear weapons used by the AFFS.
War of 3039: No nuclear weapons used by the AFFS.
Clan Invasion (3049-3052) No nuclear weapons used by the AFFS.
Operation Guerrero: Despite being outnumbered 3 to 1 on every planet that House Marik invaded, no nukes used.
FedCom Civil War: 5th FedCom RCT uses tactical nuclear weapons against the 5th Syrtis Fusiliers. Afterwards, they are universally reviled for their use.
Now, nuclear weapons are not asteroid bombs, that is a given. The point is, the AFFS has a history of fighting wars conventionally since the 2900s. Whether this is a technological necessity or a moral choice, I don't have the information to say. But from all my source material, the AFFS does not use NBC (Nuclear, Biological, Chemical) weapons in warfare. Asteroid bombs cause mass destruction on the order of NBC weapons, and I don't see why AFFS tradition and policy would be different.
While we can find source material saying the Blackwind Lancers hit Talon, destroying the Kallon Weapons plant and an Avalon Hussars RCT in the process, I see how this is more likely a false flag op. In the same vein, I think by the time the asteroid strike happens, Blake forces are so ascendant they could easily have captured all the FedSuns parts they would need to make the strike.
So long story short, FedSuns Asteroid Bombardment, Believable? Well, if you were the kind of Taurian who watched 24 hour news and only listened to government sources, then absolutely yes.
If you were a government analyst or a student of history, then no, not really.