Assign a competitor to an accout without creating a parent relationship

[Betsy]

I use accounts and accounts for practically everything because I need the data (and custom data) available to me on accounts.

I have an account type: "Competitor"

I want to be able to assign some prospect accounts to a competitor account (or visa versa) WITHOUT creating a Parent account relationship. I use parent accounts for exact business relationships--which is very important in my industry. We have many subsidiary/parent relationships. I just want to be able to associate competitors installed at certain accounts. I can't figure out any good way to do this.