Our Nigel (Shetland) would wear himself out if kept that close to girls. And yes would challenge the fencing and gates mercilessly. He's polled so can't cause the amount of damage a horned tup's headgear would, but over time he would loosen fencing for sure.
Would you be able to split one or both of the fields, so that you always had some empty space between the boys and the girls?
We keep our tup with a minimum of 2 wethers (usually 3 or 4), because tups can spend a lot of time on their own, patrolling and scenting for opportunities to work. So then a sole wether companion is left on his own. If you have 2 or more wethers, they still have company even if the tup is off on a solo mission.
I don't know if you need the tup to be a specific breed, but if not, I would look for something polled and lazy. Texel or Beltex if you want chunky lambs, or maybe others can recommend other polled breeds where the tups watch telly and drink lager for 48 weeks of the year, rather than seek work constantly.
(We wouldn't swap our Nigel Ever Ready Golden Balls for a gold pig, but he does take a bit of looking after because of his work ethic!)