Evicting tenants separately?

[Nat C.]

I have a 2 bedroom house with 2 tenants. It was previously being managed by a property manager. The PM let them get 3 months behind in rent and said they were 'working with the tenants to bring them up to date'. I fired the PM and took over myself. The tenants have been paying rent but are still 3 months behind. I'm posting a 3 day notice on their door. My question is, should I post one 3 day notice with them named as joint tenants or 2 separate notices? They pay their rent separately and as far as I know they had separate month to month leases with the previous PM. Also the employer of one of the tenants called me yesterday and said he's not going to pay the tenant his wages and will be paying them directly to me until the rent is paid up to date. I know the tenants boss who runs a building company and is a really great guy and I know he will follow through with what he said. I don't want to end up with one tenant who is paid in full and the other who is very behind and I'm punishing both. Although it's more costly and time consuming, I need to proceed with two separate eviction cases, correct?