Could you time them for about how long the injection lasts? My haldol decanoate lasted only 3 weeks so I would get the shot every three weeks instead of four. There might be some push back from insurance on that though for abilify since it's newer, but maybe your doc could help with that.
If you can do first gens prolixin and haldol come in LAIs too, and stelazine comes in a liquid but I'm not sure if that'd be easier to keep in your system.
If you think Zyprexa would help a bit though, I'd think that'd be a better plan than starting something that may or may not work/be tolerable.