One very simple strategy is to make sure every enemy province is breakable by means of wpa, tpa or marching. Often I'll find apparent enemy UBs ignored. The point is that an enemy broken by one means can be made breakable by all three.

I'm calling attackers that clear zones as "running interference". Your killers and t/m breakers are generally open to enemy attacks so I'm addressing the roving large economy provinces as interference types.

In The Virtual Kingdom I break the kingdom into divisions to simplify communication and cut down on wave drag. This is directed at less experienced kingdoms that don't understand the counter measures enemies may use to derail kingdom timed waves.

I'll emphasize that some tactics that kingdoms avoid are pure hearsay. For instance, NM is fine as an individual use barrage. You don't need to NM wave. You can use NM to achieve extra taps to place an enemy province in max gains for an attacker who might be ripe for chaining. As an individual elf cleric I would NM/NS an enemy and offer him up to one of our attackers while I attack another to compress a like nw enemy. This was done in Jerks so we were warring enemies of some reputable might. I learned this tactic from a ghetto mute who handled himself with barely any communication in kingdom. He was reportedly a grumpy old man and acted the part the few times he expressed himself in kingdom chat.