I have about 890k squad GP and the same in fleet. (Until the last day or so I had more fleet than squad and it used to be significantly more)
I have one A team, 2 B+ (not quite arena-grade), 3 B and 4 C teams. On the current map, I have to place 5 defensive teams, leaving me 5 squads to attack. I do not have the luxury of strong offense and defense and I have no room for mistakes.
My first round opponent had about 1,020k squad GP, not laser focused but still more A-, B- and C-teams available. I went balanced, he went defense. We both defeated one squad from each front zone. He won by 4 pts in the end, though I was up by 2 after the first exchange. He also lost 3 squads trying to zerg one of my B+ teams but that doesn't count against him because my squad held.
If I had gone with an offensive strategy he would have been able to clear at least 2 if not all 3 of my squad zones with his B- and C- teams and potentially take a shot at my fleet. I would only have been able to clear one of his front zones and the rear behind it, leaving him with a decisive win.
My second opponent has about 1,120k squad GP, a top-heavy roster and good modding. There is literally no way I can beat him. The only reason I am winning is that he is choosing not to fight.