a fortizar is a considerably better force multiplier than even a large POS. if you have 5 caps in your hole (and I would assume pilots for those caps) then IF someone decides to try and evict you (fortizars are a lot more of a pain in the ass to remove than any pos) you could form up 4 carriers and a fax, with citadel support you will be able to hold out against almost anyone who doesn’t have a serious grudge reason to kick you out.
10b is a small price to pay for something like that.