Fleet GP doesn't mean much for several reasons. 6* capitol ships are usually good enough to climb into top 5 in fleet arena. The increase in GP from 6 - 7* capitol ship and especially the extra ship in the last reinforcement slot can make a difference of 50k GP with little to no impact on the fleet performance. If you have the time to call 4 reinforcements in a fleet battle you are doing something wrong.
Another 50k GP can be compensated by strategy, at least on offense. No fleet I've seen so far holds well on defense though, especially lineups that also build upon strategy and not just synergy are quite vulnerable on defense. If you look at the lineup in the screenshot and think about it, you'll realize that Scimitar and KRU is actually a very good combo. KRU is fast enough to stun one enemy before it moves (e.g. vader or Biggs) and retribution from Scimitar will lock down most ship that attack him afterwards. This cripples the offensive capabilites of the enemy and can easily compensate even a substantially lower GP across the ships being used. Now that doesn't work against all fleets but it does against old meta lineups and there are usually still plenty of them around.