>>36301291Argument: If the player is offered pseudo legendaries very early, many players will simply pick them. This leads to many player's teams ending up extremely similar to one another.
Pokemon is a game that is built around team building and having a unique experience thanks to who you choose to raise. If you offer players super cool and powerful Pokemon early game that are fairly easy to get, many players will do exactly that. As such, to help promote diverse teams and playthroughs, careful placement should be considered, with rare and popular Pokemon especially.
If you want examples of how this can go wrong if attention isn't payed to this, Pokemon XY have the issue of player teams typically ending up extremely similar, with a lot of players having a XY Starter, Kanto Starter, Lucario, and only 3 other slots (That even then can be eaten up by a Lapras or something). Another super easy example is any romhack that offers the player all 3 starters before the endgame. Almost every player WILL get and use all three starters if given the opportunity.