Well it seems like you would have to take into consideration whether you are talking about actual pvp or offline raiding. If you are offline raiding someone then giga is king since you don't have to worry about anyone picking you off its back, as soon as there is a player defending giga drops in the rankings since an argent can cripple it by taking off the rider. Another example is that if you are just munching a row of unmanned dinos in an offline raid then a giga is better than a battle quetz, as soon as those dinos are manned the battle quetz becomes better. I could accept that... b
Your tiers are slightly flawed, is your S tier supposed to be for actual pvp battles or just offline raiding and wiping out peoples bases? If its for actual pvp, quetz is the very top dino. Argent and pteranadon should also be S list. They directly counter gigas and rex and every single dino that is not a platform dino just by picking the rider off. Dimorphodon should not even be in the top 3 lists for pvp, they are useless, couple chomps from anything they are dead. Yes I know they can kill the rider, but so can picking him off with a argent and then he can't get his gear back either.