
40K is also fighting you a bit because the CP is a little feast or famine, AFAIK there's nothing smaller than a Battallion that gives more than 1 CP and those all require you to have three lots of elites or heavy attack or fast attack or whatever so they're fairly skewed in their own right. Since a lot of upgrades seem to cost CP these days rather than points you might be less not able to spam your strategems and more not able to afford them!
(So clearly we should run Kill Team Battle Brothers instead so the games are quicker and the Tyranid players can eat their allies' corpses to heal wounds
Agree with Karantu that 750 might be the sweet spot. I think a single 1500 list will be significantly more optimised than two 750s, but the latter would have more CP. Two lots of 8cp vs probably 9cp? Even if the 1500 list went double batallion it would be a lot closer to the two 750s as a result, and with only 13cp to their 16.
Might be worth trying out a 1500 vs 2x750 game at a monthly games day (or whatever looks like being the preferred format) and see how it shakes out?