I know all of that, i beat the game two times and know pratically everything.
But thats not the case here, there is no usefulness on casting Espers, they take 2 Party members and are much more weak than two Same/Near Level Party member.
Also i rather spend Quickenings than summoning Espers, some Esper's Quickenings are hard or risky to try, i mean who is going to attack himself and try to get 10% of their Max HP for a mere attack?
SE Failed on FFXII Espers, the only real worth is, that breaks the Damage limit, has no waiting time and its easy to trigger.Zodiark, his Final Eclipse can take away 50,000 HP
I also know all this, was just putting the point across that summoning doesn't have to deplete all your MP, you have enough time to use a load of ethers and so on before the espers time runs out or they are KO'd. As for attacking yourself to get down to 10% of their maximum health, that isn't necessary. Just summon when you are at 10% of your HP and get out the way. Quick way of dealing a large amount of damage. Could be risky though.