Hmm...sounds to fanatical. Sounds like something the loyalist will do. But siege vessels aren't cheap. May not be too cost effective. #just saying
Sacrifice & life/death is more the Rebel's schtick- the loyals are fanatical but generally do their fanaticism while still alive.
That said, yeah they are kind of expensive. That said I like the idea of giving advent rebels some love to their seige capabilities. Of the 4 revealed factions they are lagging behidn in their ability to conquer planets(Advent loyals have culture/repossession, TEC loyals have early novaliths, TEC rebels have seige bonus TECs and a titan that positively shreds everything it looks at including planets).
All that said I really like the idea- would be difficult to balance though- make the damage too low and the siege ships become prohibitively expensive, make it too high and they can drop a planet too fast.
Also a restriction might be nice to keep it from being used as harassment tactic, sincing a suicidal pack of kamikaze-craft past front line worlds straight for less upgrades backline worlds. An easy solution could be to restrict it to use on gravity wells where advent culture is present. This could potentially be used to make advent rebel culture scary in a way completely unique from what makes advent loyal culture scary.
