there is difference between a Tank and being tanky
Tanks are low damage High CC and Health pool champions
while Garen and Urgot are Juggernauts, a fighter subclass better known as tanky Damage dealers that are immobile, juggernaughts are further split into RaidBosses who have teamfight power and FreightTrains who make up for their lack of MS with an ability that acts as a temporary mobility boost, such as Garen's Q bonus MS and Urgot's Dash on the E
Cho'Gath is one of the few champions left in the game that fall under the classification of Specialist, where their playstyle doesnt necessarily match any other class, another example of a specialist is FiddleSticks
the three "Tanks" you presented arent actually Tanks.... they are just Tanky