^mostly this

It all depends on your opponents tendencies, teams and power. Lets break down 1 land and asume both sides have 3x200k, 3x160k and 3x140k bp. If group A uses formation 200/160/140, while group B uses 140/160/200 odds are group A kills group's B 2 teams without suffering much casualties (few slightly damaged, 1 support ninja diea at most), which leeds to pretty even battle in 200v200. For the sake of argument lets say group B's 200 wins, but they lost 7 out of 12 ninjas. Which usually means no more mains or healers, perhaps 1 move1 on the edge of death. Group A has double backup, and all they need to do is kill wounded move1 and some of the other targets. It comes down to 12v4 next round, which is doable. I've personally had multiple scenarios, where such 80k lower team could finish off enemy team and win the land. At the current state of the game summons arent as dangerous as they used to be. Snake is a relic, and even toad or slug can be interrupted by high ini players.

It all depends what respective teams are using. Putting weaker teams as meatbags for 20k shield lineup makes no sense, since they wouldnt even kill the shields in the first place, while opponent rebuffs for another round. On the other hand 3x170 can beat that 3x200 if they have more synergy and additionally they counter the lineup.

There isnt one and only good strategy to gnw. There are a lot of factors to consider.

And regarding argument about fighting and having fun during gnw- people dont really seem to have fun when they get 1hit knocked out. If your "gnw guys" can guess correctly what other groups will do, medium or lower power teams can be placed in a lands where they will meet opponents on their power level or slightly lower, which means both fun for the people and win for the group.