Since you are apparently not an attorney and thus not bound by the rules of professional conduct there is no rule that prohibits you from directly contacting the other party to tell him/her this. But frankly, if I were the other party and you told that to me, I'd say I don't care that you don't want to deal with him. Your tenant is not likely to care at all what you want, either. Indeed, hearing from you that you don't like dealing with the attorney may delight the tenant. You certainly cannot force the tenant to fire his/her attorney, as I think you well know.
As for the rest, frankly your posts are not very clear as to what the lawyer has done that you think violates the rules. You have stated some conclusions like the attorney is claiming to represent people whom he really does not represent, but without seeing exactly what the attorney did it is impossible to say if the rules of conduct were violated. Without clear facts there is not much I can tell you.
I think it very unlikely that an attorney is going to misrepresent to you who he represents. It could happen, but it would be very unusual. It would be just as likely, I think, that you may have misinterpreted what the attorney said or did. I of course do not know which it is. You may raise the issue with the judge if you can show that the attorney is not actually representing the other party in that court action. But if the attorney is, in fact, representing him or her in that court action then your complaints about the attorney somehow being vague on that before the lawsuit will likely fall on deaf ears.
Ultimately it is important for you to understand that you have little control over whom the other side has as a lawyer. The job of the other side’s lawyer is not to make things easy for you. Being rude or making things difficult for you are not violations of the rules. If the attorney actually committed fraud against you, that would be another matter, but it is not clear to me that the attorney did that.