I have 3
I have 3 boxers. One in each flavor, LOL. Two females (brindle and fawn), and one male (white), which is the son of one of my females. AT first, my two females were best friends, but when the male came along, he replaced his mother and hangs out with my first alpha female. Mom was a loner anyway, they annoy her when they get stupid over a ball LOL.
But they all get along and take turns playing with each other, so it isn't as bad as it sounds, her being an outcast. They definitely keep each other entertained, that's for sure. Fighting over toys, having to check what each one is doing.
I think, it's easier to handle two than three, but I don't regret a single thing. I purchased a dodge durango, instead of my desired BMW, just because I have three now, and I love going places with them. AND -- You definitely have to be ready for alot of poop! And expense, OH MY GOD, it's amazing how fast I go through food. You don't think one more mouth will make a difference, but it definitely does. And you know those dog bones they love? The one's that cost you $8 now? Well, you need to buy two, so right off the bat, it's $16, or in my case, $24 just for bones. Stuff like that - how quickly it all adds up. Vet bills too.
But I wouldn't change my situation for the world.
Goodluck!