Sample size of two days ranked solo - pug lottery (tm), featuring ppl running base ini, no pots whatsoever among other things - is enough to judge balance on.
IB is exempt from GCDs and their buffs aren't susceptible to sever/shatter, thats macro'd into every single NerfedButtons script ran on this server, and do not cost any grudge whatsoever.
You should be looking at 6v6 - with a metric ton of salt, given quality and quantity of 6mans... or lack thereof - in regards to 'balance'.
Better yet: wait a couple of months, until fashionhammer stuff is being tossed into ranked to draw in more groups and the MMR is fully reset.
As to the realm-bias driven theorycraft:
Superpunts win games, buffs just fuel a snowball that's already in progress ('win' vs 'win more').
More importantly: SM WW >>> IB, for everything that's not double SL comp, and even then its highly debatable (protip: discount on gcleanses and kotbs superpunt, ...).
Besides the obvious:
BG doesn't compete with IB for spots, don't waste people's time with mirror matches in a vacuum; different realms, different synergies.
EDIT: Grammar, spelling, words. I lack coffee.
EDIT: That post came in while I was typing mine:
In my book 1v1 arguments are irredeemable. Just why.