the meld priority for GNB is Comfy SkS > Crit > DHit, basicaly you want to have a GCD acord to your own ping to execute the rotation properly, right now it's around 2.40-2.42 for players with good ping, if you conection is average you probably should aim to a 2.39 or less.

for crit and Dhit most builds right now archive high crit with bis and meld mostly Dhit so the best answer will be have a 50/50 and you should be perfectly fine as long as you keep focus on both stats when you get comfy SkS.

for tenacity and determination you can freely ignore them, know how to use you defensive kit will grant you way more benefics that tenacity and determination is inferior to Crit and Dhit, have fun with the job ^^