I don't think he'd like seeing another man take his place at all.
But, I urge caution with regard to who you tell that he needs to be a man. In my mind, a man is someone who honors his commitment and cares for his family and busts his ass to do whatever it takes to make the sitch/R/M right.
Unfortunately, I have told H on many occasions lately that I wish he would just be a man and do his duty.
Unfortunately, that is probably the single most hurtful thing I could have said to him, and even now, months later, I am paying for it. Even last night, when we were out just having a nice night, he brought it up again.
Maybe it is what your H needs to hear, but somehow, I have a hard time believing that he'll be able to really hear what you are saying and instead, is just going to hear you using words to strip him of his man parts.
I urge caution, then. I agree with you in that he is not being a real man, but I don't know that you need to tell him that. At least, not in so many words.
Again, I wish you the best of luck, and I genuinely hope that today (Easter) is good to you and your family. Kathi