Ok, fair enough. Then I agree there should be a control aspect to the summons (as there is for example with the Evil Essence Demon summoning lists); in fact I see the summoning circles and the controlling of the creatures summoned to be the core aspect of the class. I guess I don't really see the glyphs and words of power as integral to the class -- I don't really read 'Summoner' and think of someone writing glyphs on stone; I see someone drawing a circle and summoning something in it.
I do see some kind of control mechanic already existing in the RM2 Conjuror's summoning circles though. The spells say that animals and monsters are summoned 'to do his bidding' (i.e. the caster's), though Demons and spirits are not. What the Conjuror can do with animals and monsters at least seems a bit better control in some ways than the Evil Essence demon summons, because for the demons, you have to cast a second spell to bind or master the demons. With the Conjurors' animal and monster summons, by contrast, the creatures seem kind of bound already. And then of course the RM2 Conjurer gets his own separate Demon Mastery list to control demons.
Anyhoo, all of that is just to say: I'd personally prefer a Conjuror/Summoner who was more focused on summoning circles -- maybe one for summons, another for control of creatures in the circle, another for warding/protection vs. things outside the circle (very useful for summoners of course); maybe another list to banish summons and extraplanar creatures; maybe another to use the circles as portals (like the RMSS Summoner has), etc. I'd actually be totally fine if they had no glyphs, wards, or words of power at all, since I think that would make for a more unified class concept. But that's just me.