[@Sho Minazuki]

I just think level should be variable and kinda assumed, not a real thing

Its assumed they are a higher level if your pokemon cant beat it easily.

Its assumed they are a lower level is your pokemon can beat it easily.

Its assumed they are equal if the battle seems evenly matched.

I think levels are only necessary for playable RP characters so they can't make up that their Pokemon can beat yours because its "higher level", even then everyone should have around the same assumed level.