How about you don't decide what's best for everyone.
@Legasss123 I like kids at weddings, but then I like more traditional weddings, service then party in the church hall. I may be a 70's child with lots of good memories of family weddings!!
But this is your wedding!!
Bear in mind though, it'll change what your guests can/will do. Some might not be able or willing to get childcare, so may have to decline. As long as you are ok with people that have/choose to do that then, that's fine. What's not fine is getting arsey about oeople not being there for your big day, because they can't/won't get childcare. Obviously it's even more difficult for people whose 'babysitters' are also at your wedding.
have you asked the venue about options for children? Some will do more children's party food thing in a side room, rather than a 3 course meal with the adults. Which can work out better ££ & more fun for the kids.
but if you're worried about the more feral kids, then 'no kids' is an option.
if his sisters 'kick off' then just ignore & if they carry on & on & say they're not coming, in a stamp, just say 'That's a shame, but we understand'
Do NOT ket the loudest ones bring their kids while the quiet ones accept your plans!!
or hire the village hall & have a party!! 😉