FE 8 - Summoner Class Discussion

I've just completed my first FE8 run, and around chapter 16 I promoted Knoll to a summoner because I wanted to try out summoning, and I haven't found it very useful. Granted, Knoll is still a pretty good glass cannon, but the summon command itself has been lackluster for me- in exchange for wasting a potential combat round I can create a summon with pitiful attack, late in the game, that dies in one hit. Is there some AI manipulation I'm missing? I can see it being useful to bait enemies occasionally, but Duessel or Kyle (GK promotion) can do that just fine. Thoughts?