[SkooL]

Yes. Co-Owner is improper if you are wanting the "owner" to wield more power. The people you work with, they are your co-workers, and you are their co-worker. You are all equal workers, but are co-working together. Each should have an "Owner" tag. If you are the supposed "owner," you are co-owning with someone else; so you are a co-owner also. If the "owner" wanted to make it proper, he would have to use something such as "Vice Owner."