Okay, I feel like I have to make this thread. This might get a bit technical, so if you don't feel like reading the entire thing, I summarized my main point in bold. I hope this makes staff at least think about balancing the kits, and makes the experience better than it was before.

So, kitpvp is defined as a free-for-all, large-scale arena in which people run around killing each other. Each of them has a "kit" of items to give them an advantage against the others. My examples here are going to be the generic ones, Knight, Archer, and Brute. Here's what they would normally have:

Knight: Iron sword, iron armor
Archer: gold/leather armor, bow and some arrows, wooden/gold sword
Brute: Diamond armor and stone/wood axe

The problem is, the archer can bowspam, and thus a skilled player, especially a if they're proficient with bow, can't lose as archer unless they're fighting other archers, or get triple-teamed. Here's the key to balanced kits:
Every Kit, no matter what it's called, MUST have a decent Melee weapon, a Bow, and more or less the same armor.
Now, complete balancing is NOT possible. Whether 2 kits or 10, there will always be that one kit that's either uselessly weak, or overwhelmingly strong. Players abuse, and break perfectly good arenas/kits to make the experience worse for themselves. The solution, which I've seen really well done on multiple uhc servers, is to either make random kits, or rock-paper-scissors kits.

Rock-Paper-Scissors, just in case you might not understand the concept, is a game where two people pick an item (rock, paper, or scissors) and try to pick the item their opponent loses to. What makes it fun is that each item beats one item (scissors cuts the paper) but loses to another (scissors is smashed by rock) therefore, no matter what you pick, there's always someone who can beat you. Here are examples of MUCH more balanced kits, keeping in mind the main point (in bold) and the Rock-Paper-Scissors theory.

Knight: Iron armor (Proj. Protection 1), iron sword (sharp 1), a bow (16 arrows) and 1 potion of health 2
(this kit is good against archer, but weak against brute)
Archer: Iron armor (Protection 1), iron sword, a bow (power 1 maybe), and 1 potion of regen 2 for 22 seconds
(this kit might need nerfing on the bow, just extra arrows, testing required. it's good against brute, weak against the knight)
Brute: Iron armor (protection 1), stone sword (sharp 1), a bow (16 arrows) and 1 potion of resistance 2 (22sec?)
(this kit is a beast against knight, although dealing less damage, but still gets shredded by arrows, might need one diamond armor piece, more testing needed)

If more kits are needed, I'd suggest some sort of cleric kit who gets golden apples and has the gear of a Knight, maybe a few less arrows to balance it out.

All in all, staff will need to test the kits and plugins, and have avid pvpers test the balancing before a full-serverwide release. (oh, quick thing I forgot: this balancing was designed as 1.8 balancing, in 1.9 update just add shields and nerf archer a lot)

I hope high staff reads this and considers these ideas (especially @LordInateur and @KlutchDecals)
and puts someone capable of creating a fun, balanced kitpvp experience for everyone to enjoy

oh yeah also the anticheat could use some work