tbh white was easier to win for me
all you need to do is figure out when to strike,build a pawn wall,have patience and wait for opponent to strike first(sac a few pieces to get a rook or a queen to the back rank,since the back two role of the pawns are basically useless unless they survive till endgame,forget them,push the front pawns and attack
remove the defender when possible and then push up the pawn chains,even if the first wave fails the second wave will come fast as you have build up the pawn wall,start attacking from both sides and just PUSH
getting 1 pawn promoted is enough to draw the game,2 is better and have a chance at winning as you have no king
(obviously I dislike playing as black)
It's VERY hard to win horde as white. Its a very unbalanced game, but still, its possible to win if your opponent mistakes.
https://www.chess.com/variants/horde/game/14799734