Glass half full has used a tier maker to give a view on the various teams in a youtube video.
https://tiermaker.com/create/kill-team-chalnath-tier-list-1354090
To summarise his list with the changes he wrote in the comments
Tier 1 - 'stealer Cult; Harlequins; Custodies; Kommandoes; Pathfinders
Tier 2 - Veteran Guard; Hunter Clade; Warpcoven; Novitiate, 'Nids
Tier 3 - Grey Knights;
CSM;
SoB; Demons; Dark Eldar
Tier 4 - Tau; Forge World; Orks; Necrons; Kroot; Guard; Death Guard; Thousand Sons;
Tier 5 - Marines; Eldar; Deathwatch
I would do it slightly differently.
(Add Scions/Scions&Guard; Kroot to tier 3, Knock pure Guard to tier 5; Deathwatch to Tier 4)
Thoughts on your own list?
Anyway, do you think there should be any sort of team balancing?
I think there should be some straight team changes and also some measures to help poor teams in tourneys/Campaigns.
For balancing separate thread for Eldar and Marines.
For multiple mission balancing (Tourneys/Campaigns) I would have one that helps poor teams/players. Essentially for every match you lose you get an EP, the third match you lose you get a
CP instead.
If the teams weren't altered I would give Eldar and extra
CP and Marines an extra EP.