Honestly, I wish Riot would take a good look at their 2 balanced yet overlooked juggernauts
in particular & take notes on what they did right.
I'm not by any means saying Nasus isn't a well balanced example, he certainly is & I'm glad to see the stacking mechanic on Garen's W. However I feel Mundo's overall mechanics are a closer to Garen.
Mundo is tanky yet deals decent damage, lacks a gap closer & still manages to force you to focus most of your cc on him in teamfights, most importantly he has counterplay throughout the match. He's definitely annoying to face, but less oppressive than most of the other juggernauts.
Mundo's passive & ult gives him plenty of health regen, a trait we see in Garen as well. Likewise Mundo's W reduces the duration of disables & does AoE to those near him & add in Mundo's ult giving a move speed boost. So similarities to Garen's Q & E, just arranged differently.
With so many similar traits to Garen, what makes him less oppressive & how to apply some of that to Garen is something I hope Riot will look at.