Quick question about Warmode sharding

I was wondering if anyone can tell me how it works. I mean I guess RP realms are on their own, so you can only see people from other RP servers. Which is overwhelmingly alliance so there is little point to go for warchests as horde.
But does it work like that on other realms? I do not remember last time war chest was contested on server like Drakthul. Where it is almost always horde

I wish i understood this because i have characters on a few ‘full’ pop realms that are 90%+ either horde or alliance every encounter i have in world pvp it i am always outnumbered 5 to 1 so the realm balance makes no difference at all.

Realm balance doesnot need much in retail

Less players use WM on, therefore those players tend to be shoved in shards together. The shards dont always seem very balanced despite Blizz aiming to make it fair. I also think there aren’t equal numbers of players to pair i to the shards.

The bulk of the playerbase use WM Off. I find I actually see more players from my own realm in WM Off.