That is definitely a grind. First thing I did was start using Thunderlord as my Invader deterrent. Wasn’t perfect, but it gave me enough confidence to even hunt invaders. Second thing was to bank any motes I got immediately. Wins will eventually come and will largely be dictated by the strength of your invader. You cannot really control this, but you can control your depositing of motes. Once I got that part done, I just played the game and waited for my teammates to achieve the three wipes of an enemy team. Surprisingly, this did not really take that long. Nothing made my Gambit experience better than stopping my fear of the invader with the challenge of hunting them down. Sure, I failed more often than I succeeded, but it made the invasion less of a stress event. Malfeasance is definitely worth it. Slow and steady and it will be yours. Good luck.