To follow on @Tommi’s points, we often get new creatures in the game that aren’t available other than for REAL money like the Leedsichthys or the Gen 2 T-Rex showing up WAY more than would be realistic if these were all real players. Sure, there’s a few whales out there paying for these creatures. But with new releases, they show up all the time for ALL of us. There’s just no way THAT many players are paying money to get stuff in the game. It is however quite reasonable that Ludia uses these creatures as opponents to entice players into paying money to get them.
Likewise the point about the level of the opponents. Sure, we all have a few creatures we haven’t leveled up all the way. But the majority of players that have played for any length of time aren’t doing PvPs with their best stuff. The ones we do PvPs with therefore are almost always fully leveled up. You can discount occasional non-leveled up opponents but we get them ALL the time. Almost every match. The same is the case with weird team lineups and actions… sure even real players do bizarre stuff from time to time. But not at the frequency that we see these in the game… which is VERY often.