What are some good strategies for playing 1v1 or 2v2 on large or very large maps that do not have super-bonuses, so any one bonus is not critically important?

Might help if you linked what kind of map you're talking about. Most of the large maps have super-bonuses. (like https://www.warzone.com/Map/21760-Limalias-Gargantuan-Westeros and https://www.warzone.com/Map/6496-Issanders-Huge-World )

Though generally you'd want to control any chokepoints that are easy to defend, and any bonuses you can quickly cross large distances (like islands).

Expand as much as you can. On large maps, income you gain by it prevail eventual lossess in fight most of the time.