Spirit: I’m no expert at PVP, that team I run just synergizes well. As mentioned, when I play that team I mostly just put Nightingale on autopilot and simply pick targets for her, and spam the skills buttons.
When I play with my other teams, I manually pilot more often, depending on what I’m doing in real life. I play every team different though as far as who to open with, when/why to switch hero, to whom, etc…
A lot of PVP is just having a good team: a team that works well together, is balanced in terms of DPS/Support/Tank, is balanced in heroes’ levels, has diversity of elemental damage, and has answers to common problems (Flatline, Mandrake, etc…).
Most of the rest of PVP is prioritizing in any given fight who to attack first with whom; and that’s where it’s very complicated. It depends on many considerations. If there is someone I can kill very quickly, like in 1.5 clips or less (a low HP, high DPS target like Clyde/Siren for example) that might be the first priority. In another match, killing someone annoying like Flatline, Ifrit, Mandrake, Caine might be priority #1, otherwise the enemies won’t die (Mandrake) won’t stay dead (Flatline/Ifrit), or must be ignored (those supported by Caine). In another match, killing somebody who is going to get way stronger later (such as Cinder, or Castellan) might be the priority. It all depends on what’s achievable too. If I’m pilotting Panzer, I might go for the quick knockout on Castellan, because I can achieve it. In contrast, if my mech DPS unit is Dogface, I probably can’t kill Castellan by the time he receives his first heal/shield, so I should target a support I can kill quicker first. The real challenge comes when you encounter multiple first priorities at the same time. If you’re attacked by Mandrake, Flatline, Ifrit, Caine, and Castellan, who do you attack first? Tough choice, but the right answer probably depends on who is on your team as well.
By and by, I’d say in most games the key is turning it into a 5 v. 4 ASAP. There are exceptions though. I’ve lost plenty of matches where I take the first two kills, and the enemy still wins (seemingly coming from behind). In my Keep Castellan Alive team, the goal in the beginning is just to stay alive until the Sentry Turrets start to take over.
Every team plays different. Experience is your best teacher. I’ve been playing this game for like 2 years.