while there are less summons available the summoner class makes up for it in the variety of infused incarnate powers. Missing a water elemental? infuse the incarnate with water then. Missing fire? then infuse with fire. While its not a complete 1 to 1 it opens up many possibilities. Summoner appear to be powerful. You can do still do a marksman with a summon combo by investing point(s) in summoner instead of something like geomancer.
So while I was initially put off by the fact that some summons were pulled I was very pleased to see with what it was replaced with.