
Hi,
I don't know much about Beagles in particular, but I have been obliged to raise 2 littermates - and it has been
such hard work! Two puppies together aren't double trouble, they're trouble squared - what one doesn't think of, the other will, and then they work as a team! You cannot watch both at the same time (unless you have independently swivelling eyes, like a chameleon) so you can't prevent all the damage - and if you leave them unattended you never know which one has been naughty.
You have to do twice the training, because you can't train pups at the same time - they must be done separately. They tend to bond more with each other than with you, so they are less responsive to you - and Beagles have a reputation for being independent anyway. Then there are the hierarchical problems that develop as they mature - it has been bad enough with my two males, but two bitches can end up hating each other and one having to be rehomed, as a friend had to do, who tried it.
So from my experiences, I would suggest they get one puppy at a time, with about a year between them.