How to play with knife?

Hello brothers, I bought the game two days ago, loving it I am almost on second prestige on sniper but for the love of emperor I have no idea how to utilize knife well. I usually just use it to stack my armor with Holding RB into gun finisher on minoris. But on majoris or higher level enemies it doesnt do a lot. Difficulty I play is lethal and absolute and hard strategems (if it matters). I usually top the distance damage chart, but in melee damage i am like 2k while the rest of the team is 10k. Overall in the end i am like 15k all in damage wise while the rest is around 20k so I am basically trailing 25-30% damage wise. What are the best combos maybe i need to change some perks or use different knife. I am using fencing knife from the highest tier.