Excellent novels that I find where the MC is transmigrated/reborn into a orc/beast world. Majority of these are set in a somewhat or really primitive world. Worlds that are full of men only with so-called females(men that can give birth) or with real females. Some are community/tribe/kingdom building aspect which is very interesting. Some can also focus on family improvement more. Incomplete stories can be found elsewhere. You just have to search for it.