3 not tanks. Juggernauts focus on dealing damage while sacrificing other things, like Nasus and Yorick lack the teamfight power of a true tank. If a champs kit is focusing on dealing damage, like Urgot, Yorick, and Nasus (All juggernauts, subclass of the fighter class), then of course they’ll compete for highest damage dealt.
Malphite and Ornn deal primarily in AoE damage, which allways fluffs numbers. Compare, say 1,500 damage from Malphite in a fight, but 1,000 from Syndra. Malphite will have hit multiple targets with all but his Q, and so his total damage dealt is reflective of that, but he might not get any actual kills, because that’s only an average of 300 damage per enemy (if hitting all 5). Syndra will hit 1,000 on a single target.
In Ornn’s case, all his damage also comes from his W, which Riot made deal 20% target max HP damage spread across all 5 ticks (4% per tick). He’s locked into a single direction, so it can be evaded. But if it hits multiple targets, hos total damage will be similar to Malphite’s.
Tahm Kench is primarily a support tank, and he does deal less damage unless he gets 3 stacks on you and you stand there letting him auto you.
If you want people to take this argument seriously, stop using Juggernauts, and show some actual numbers, because Ornn, Tahm, and Malphite are still a good chunk of the way down when looking at damage dealt.