Well at least you can do it with only one loop.
-Start loop "Players"
On Loop "Players"
+Compare to alt val A of "Character" == loopindex("Players")
+Compare to alt val B of "Group.Equipment" == fixed("Character")
-Set position of "Group.Equipment" to 0,0 from "Character"
Replacing fixed("Character") by whatever id you use to match equipment to a character.
A lot of many-to-many code uses two loops, but you only need to loop through one object to turn it into the one-to-many events MMF is good at.