I’ve never played ground wars but judging by what Xyturial said it’s basically snow wars but with eggs and a spring theme so here are some suggestions (this also applies to snow wars but obviously modify to fit the winter theme for that)
You can unlock these by getting enough kills, breaking enough blocks, or they can spawn on the ground and you pick it up if you step on it or maybe tap on it.
After getting maybe 5 kills you could unlock something that can destroy multiple blocks at a time (like instead of throwing eggs maybe a chicken launcher >:3) but maybe you can only shoot it once or twice
Blindness Egg (maybe it could look enchanted) when you throw it if it hits a player they’re blind for 3 seconds ish
Instant Wall Builder, this could build a two block high and maybe four block wide wall
Double boosters, if you get one then it doubles the amount of blocks or snowballs (you could get a block 2x booster or snowball 2x booster) in your hotbar/inventory
Player Launcher (maybe looks like another enchanted egg or like an egg rocket launcher looking thing) when throwing it at someone it shoots them up in the air like what happens when you try to cross the border
- Losing team can have their colored blocks rain down (this might cause collision problems though) to help them build
- Losing team could have their snowballs and blocks increased by 20%
- Harder to destroy blocks. Besides concrete, maybe concrete powder, brick, wool, etc. etc.
That is all for now, I might update this later. Thanks for reading!