Thank you!
I've had ducks for a long time. These guys will join my other "soggy chicks" outside when they're about 3-6 weeks, depending on the weather and how their down growth is doing. They need that white fluff. Yes, they will use the heat pad. The heat pad hovers around 100+ish degrees and only heats what is touching it. The ducks heat up and then have to walk around and cool off. The room is about 66 degrees. They don't normally cluster, but my tsc ducklings are afraid of people and I've kind of chased them into the corner for the picture. Chicks will use my $15 walmart heat pad too, usually crafted into a tunnel. I like the pad because of the reduced fire risk and because babies brooded with natural dark/light seem to be calmer and more relaxed. It's good as long as the inside temps are normal. They just need a little boost.
I have 13 goats presently. Too many/5 bucks, and 8 does. The new goat will make 14.

My husband mostly leaves me alone to manage the animals, so I don't have to convince him of much. I know what I can handle while keeping everything in the condition I like. We're going to try to break even or make a profit this year (lol).
In regards to convincing your husband, I know I've heard that having a lonely goat will make them break out to find company, in your case it may be on the other side of that fence with those desperately seductive does. That may be compelling to your husband. If you can swing it with him you can always keep both bucks until you decide what you want to do-or indefinitely. It is your herd, and it has been done before. I can't judge. Just be aware that selling goats is very difficult in the winter, bucks especially, so if you are going to sell one, sell before or after winter before the hay for the year has stopped coming in. Your one buck MIGHT be okay next to the girls with no pen mates, but mine would get desperate to get them, not just for mating, but because he's a goat too and is desperate for the head smashing and bullying and alliance forming and snoozing with the BFF's in the sun that goats do.
Then there is the issue of uncontrolled fence breeding out there, but my guys aren't exceedingly talented at wooing and luring the right end of the goat to the fence for that so I can't say much about it besides the issue existing. B&B would know more about fence breeding. I think she dealt with the results of an incident if my memory serves. A hot wire or two might prevent this issue.
I don't think a buck eats that much more than a wether, if he's willing to let you keep a wether with your guy, so by the slippery slope fallacy a second buck would be okay too???
Convincing one's spouse of anything is difficult. Mine is a remarkably stubborn man, but he respects my space and my little "kingdom" outside so I don't have to convince him of much. I wish you luck is the most I can say. Worst case scenario, you will still have your one buck. (may or may not worth mentioning, a buck apron might be an option for occasional romps here and there might be appropriate, but I'm not sure I'd want to rely on them to control breeding long term).
All that being said, we on here tend to be enablers and you know your situation and spouse better than us. I hope you guys can work out what you want to do. (secretly I hope you get your goat dreams here)