Seems quite an interesting take on harem. Both dude and his waifu are "men of taste". They like the same things about women.
Early on it seemed like the wife is the protag and will have a harem, and MC will be just a "fake husbando" that in reality is a living dildo to give pleasure to her and her harem.
But it seems that the mistresses also have feelings for MC (or just his dick, didn't read that much into it yet XD), and with his abilities to strategise he will win their hearts in the long run.
Dude already (at least in what I saw in recap videos) found the 2nd harem mistress for his waifu, and she liked and jumped bed with her near instantly, and then them 3 horndogs used MC for pleasure. It seems they will have a "proper" poly relationship, where both wife and husband are horny 24/7 and they add multiple harem mistresses for themselves.
Thus there is a hope there won't be any drama there of girls feeling inferior to others etc, or at least wife will be always the number one, cause her "position" is different than the rest of harem girls.