Why is Jarvan's primary tag Tank instead of Fighter?
How is a guy with high base AD damage and 26% armor shred on a low CD a Tank?
Tank/Fighter?
250 + 240 + 450
Tank/Fighter is someone like
not 
Other junglers that fit the same role as Jarvan that have the same qualities and damage potential that he has:
Fighter/Assassin 300 + 10% Maximum Health + 130 (2 charges) + 450
Fighter/Assassin 225(+60% Total AD) + 210 + 275(+15% Enemy Current Health)
Fighter/Tank 150(+110% Total AD) + 240 + 800(+440% Total AD)
Assassin/Fighter 240 + 250 + 350
Fighter/Tank 200% Total AD (technically) + 400 (average of min and max) + 220 + 425
His damage is on par with all these other junglers that fill his same role, why is he classified as a Tank?
Lets look at a real Tank
Tank/Fighter 300 + 55(+10% Total Armor) return per attack + 195 per second for 8 seconds
is not Tank/Fighter, I don't think he qualifies as Fighter/Tank if
don't