I have a non neuter dog and a neuter dog living together is that bad?

my best friend got echo( neuter pomeranian) at the shelter for my b-day My husband and I have had Junior (non neuter chihuahua) for about two years now my chihuahua doesn't go out other than the back yard and he does pretty well we agreed to Echo so that they can be companions but I'm afraid one of them being neuter will cause an altercation ...the only reason my husband won't neuter junior is because it is his first dog's baby and he might want further babies from his original breed plus he loves Junior tenderly and wouldn't give up keeping his generation in the family I still don't have Echo yet but I'm wondering if this is a bad idea ? I wouldn't give up Echo either originally who was gonna be a girl... but after being spayed she died after the surgery. so we went back to the shelter and decided (we: me and my best friend) it would only be fair to rescue her brother (echo), what should I do? what will happen will my neuter dog pee a lot because my non neuter one does !