You must not have run into teams of high-level japanese players. Dayum.
He could just have skills. After I adjusted I was beating the level 19 Japanese guy who was way ahead of everyone with just my basic gear, and I didn't know how to use specials yet.
So far my tips:
1) If you're bad at fighting, get bubble first.
2) Spray-n-swim, spray-n-swim, probably with faster alternation than you'd first feel like doing. You'll cover more ground and not run out of ink. Perfectionism in coverage isn't worth the time or ink.
3) Practice setting up an aim on stuff while moving/swimming in single player and weapon testing mode. Not being in the heat of the moment lets you focus on the particulars of controls, and when those aiming skills have taken shape, they carry over, but they form a lot more slowly if you try to develop them in anxious situations. Most important is accurate adjustments while running backwards.
4) Obviously at like 2/3 through the match, you should only be painting over what your enemy has unless none is in range, at which point it's fine to paint uncovered walls on your way to enemy-painted ground.
5) High ground is pretty OP in battle. Maybe not a perch (aside from easy quick coverage of a big patch), but just a slope up can give you a real advantage since it's all arc shots.
6) If you realize there is a fight on the other side of the box next to you, but you have a clear path into mostly enemy-painted ground. Don't go chasing the fight. That's their problem, and if that enemy does some work, it's closer to your spawn and more likely to be fixed. Take your far-out painting opportunities.
7) Use grenades to control their movement options. It's trickier in here than other shooters since it uses up a big chunk of ammo, but the swimming required to refill also adds a stealth element to what you do after you toss the grenade.
