The original timeline was written by the Council of Wizardry. It is also very humancentric.
Their history only goes back so far…basically in that part of Astlan Wizardry was lost for a long time and had to be rediscovered/reinvented. So the vast majority of their spells have been developed since the time of the Anilords. Some has been imported.
But there are other groups of wizards, with different spells that do similar things. Think Western medicine vs Chinese medicine, etc. The laws of Wizardry are what they are, like the principles of Physics and Engineering, it’s just a matter of learning the rules and utilizing them, so it’s like different groups discovering the principles of Engineering at different times.
On the other hand animages are simply natural talents/disciplines that harness animus and mana without a preset patterns/engineering. So there were wizards summoning demons in Astlan, thousands of years ago…just not so much in that part of Norelon within the time that Orcus has been gone.
What I can say about animage summonings? Because of the risks, they were generally lower demons, and a lot more bargaining was going on. Think Faustian deals and such.
And of course, priests and shamans and druids could also do it, in most of those cases though there are motivational difficulties in why would they want to? However, the hermetic druids would have rituals very similar to a priest or wizard to contain demons. And shamanistic druids/shamans would have had some as well.