What does it take to make juggernauts competitively viable while not being broken?

In this split of the LCS i have watched every single CLG game along with most TSM, C9, KT, and a spatering of over games mostly in korea. In that time I have seen 3 juggernauts in total Mundo, Trundle, and Olaf, with only Olaf ever being anything more than a cheese/pocket pick. Last season it was pretty much the same juggernauts that were played it was just that trundle was a bit more prominent, and mundo had an early stint as an op before quickly being nerfed. Udyr also showed up but at the time but he was also ridiculous at the time as well in solo que to a frankly ridiculous degree (I was bronze 5 at the time so I may be wrong on this).

Out of the three juggernauts that has seen play in both season 6 and 7 only olaf and trundle were good picks in both season 7 and 6 while also not being to overbearing in solo que at the time. This is a pretty short look at the competitive scene and its history with juggernauts but going to far back means your looking at a completely different game from what we have today.

Are these two juggernauts a good mold for other juggernauts to have traits built around? Or does the state of the game need to be changed fundamentally for more juggernauts to show up in LCS?