It's not easier than you think
First of all are you guys talking about splitting americas into two groups making NA have 6 teams (SEN, C9, NRG, G2, 100T, EG)
and give SA 5 teams (LOUD, KRU, MIBR, FUR, LEV)
which means you would have to bring one more SA team into the scene, which would be unfair to tier 2 NA teams
or give each region 10 teams each
However this will definitely spark outrage between other regions as only one team from other regions can be promoted via Ascension per year, while both NA and SA have multiple teams promoting per year, theres just no way riot is gonna let this happen
Not to mention the brackets
Currently we have 4 regions which is perfect for a 16 team bracket or 8 team bracket
If we have 5 regions then we would have 10, 15, or 20 teams brackets which is a nightmare to arrange
these are just some problems i thought of off the top of my head, im sure there are more complications