I'm in a game right now and just used summon monster 3 to summon 4 creatures from the summon monster 2 list. However, we have two enemies and I want to divide up my forces to deal with both of them. My question is, how do multiple monsters being summoned with one spell work with respect to their starting locations? Do I open up one portal and they all come flooding out (meaning they have to appear adjacently or otherwise as close as possible)? Or can I make them each show up individually within the range of the spell?
Also posting via the wizard casting the spell.
The summon monster spells have no listed limitation on how the monsters are spread out apart from the spell's range.
However, many GMs might use the same limitation as the planar ally and planar binding spells, which state that "no two of which can be more than 30 ft. apart when they appear."
Either way, you can certainly have them appear next to separate enemies.