The reason your code didn't work is because you're comparing 2 instances of the same type. To get around that, you can either "pick instance x" x=0 being the 1st instance, and x=1 being the 2nd. Or put the instances into a family, then you can compare the family with the instance... so it'd be like "if MinionFamily OVERLAPS Minion then..."
But yeah, arrays will work for this but will require you to change a lot of your code and if you haven't used them before, or have little experience with arrays in general, then you'll have a big hill to climb.
EDIT> Just realised you're using the free version. Families are a no-go then but my first suggestion will work (pick instance x)