Out of the 264 wins I have over 800 games. I recorded my wins and losses on a spread sheet.
SS: RDM
RDM: You know the saying: Float like a butterfly and sting like a bee? RDM must haver visited America because now it's move like a jet engine and hit like a nuclear weapon. Team effort to kill them. Silence + Root strong against them.
S Tier: WHM, WAR
WHM: AOE Stun, First to LB, High damage, Endless heals. Use DRK/SCH to counter or chase away.
WAR: High damage, AOE CC, Sustain. Use DRK/ SCH to counter them. Burst works on warriors.
A Tier: DRG, SAM, NIN, SMN, SCH, DRK, MCH
DRG: High damage, High sustain. Burst and DOT when in the air to continue doing damage to them. Roots and Silence works well.
SAM: Two types of CC, shields, always has kill pressure. Ignores guard. DOT them to remove shield and them focus them. When LB is up use silence and root to stop them. Stun doesn't stop LB.
NIN: Highest damage every 30 seconds if you let them set up. Weak to stun, silence and root. You can stun them mid ultimate animation. Keep ninja at a distance to force them to use LB from afar to easily deny. DOT to stop from stealth.
SMN: Will absolutely ruin your team if unchecked. Focus them, do not let them aoe the crystal. Weak to Burst, Silence and Root.
SCH: Can't be solo'd, can influence fight with hp reduction and mitigation. Need to be aggressive. Focus on bursting them or away from your healer or bait out mummify before healing.
DRK: Good at countering top meta. Best stallers in the game. Apply dots and stay away from their zone. Weak to range and CC.
MCH: High damage if you leave them unchecked. Weak to root and silence, and can't duel well.
B Tier: MNK, RPR, AST, SGE, DNC
MNK: Good damage, can clear a point from stalling. Weak to burst.
RPR: Highest damage in the game if left ignored. Weak to burst.
AST: Good at influencing fights, good at keep team self sustaining. Requires team effort. Kill them first to deny buffs.
SGE: good damage, can control an area well. Needs to be selfish with their own buff to sustain. Focus when their LB is UP and force them to use it away from crystal.
DNC: Low damage, but can peel and survive very well. Ignore them unless ult is up. Weak to burst, silence and root. They can buffer dash a stun.
C Tier: BLM, Paladin, GNB, BRD
BLM: Takes too long to ramp up, can get high damage, but too easily picked off, and even when spamming frozen to slow/sleep they still can't kite. They lack upfront damage for kill pressure. Pretty good at unleashing damage when contesting a point and people are forced to fight on the objective, they can top charts when focusing under those conditions. Very weak to CC. A lite version of SMN.
PLD: Weak all around. Respect the damage they get from Ultimate. They can hit surprisingly hard with it. Everything works against them.
GNB: Second highest tank damage, can be kited though. Extremely weak kit but can ruin you if you let them get close.
BRD: Weak damage, weak mobility and weak team buffs. You're a CC bot, have to silence and root one of the OP jobs to have an effect, but their CC is top level for sure.