to be honest i thikn taric is even easier he doesnt even have to hit skillshots just stun pop W and ulti if all in low hp u heal yourself he is retard proof
At least early game Taric has risk built into his mechanics. He can E someone trudge up to them and W them, but then he loses his armor and is squishy in range of a no longer CC'd ADC and/or Support and is reliant on his ADC to kill the enemy or cause the enemy to run away. Leona can get half way out of range of most ADCs before her stun even wears off and she might have her powerful free tankiness ability still on if she was only poking and not trying to all in. The only risk Leona has in a 2v2 is if she's CC'd (which is the risk every melee support has), and then only then if her tank buff is on CD or she's horribly low on health.