Since we purchased a guardian, Gives us more sparing chances with active guardian (and make them a bit cheaper if possible). All we can really do is test out our bases and do story missions. Theres always many reason to purchase a Guardian, but I would love to do more things in the mean time and sparing is it.
Some benefits to this idea
-Test out different units on your base
-Move around your defenses for optimum protection
-Test out different placements for traps
-Understand the movements of different units
-Practice makes perfect in PvP battles
Hope to hear more ideas and benefits to this idea.