A) Gambit prime is 50% PvP at most B) Apart from unlocking the tiers, Gambit is in no way required to do Reckoning. I mean, if you want good rewards from it, you will need to get synths which are best obtained from Gambit Prime, however there are a couple of bounties that give synths without any Gambit C) There is a very clear in game reason why Gambit Prime is tied to Reckoning. To put it simply, it’s Gambit mans ship, drops gear related to Gambit, so of course, Gambit is involved