TB - Ship Platoon Paywall

I don't think you're expected to be able to complete everything in TB without being active purchasers of content (that is, new characters/ships).

That being said, the price is awfully steep for those three, since you can't get them even from crystal shipments.

Per Kozi, if you don’t have those ships, you are supposed to go recruit players that do have them. I have requested and am still waiting on the list of players that have the ships, so I can try to recruit them.

Moved to the TB sub-forum.
Keep in mind that platoon bonuses are certainly not required to progress in TB, they merely provide a bonus for certain areas. As such, those rare ships are never really required for TB. Like most game modes, a full roster can make things easier, but is not a necessity.