Independent brokers, advisers, lawyers, accountants, and all who might join a "multi-disciplinary practice" (or networking alliance) seek strength and efficiency working with kindred spirits facing the same issues.
Ethically, it can be argued that these arrangements make sense, except for the idea that the participants are bound somehow to bring in their fellow alliance participants on cases, who may not be the right or best professionals for that case. By performing on an ad hoc basis for each client, rather than within a multi-disciplinary practice (MDP) (or networking alliance), a case can be made that this is more advantageous for the client. I believe you can see that both methods have merit, presuming some explicit guidelines are adhered to, such as competency and suitability of participants, and full disclosure about compensation and conflicts of interest are made.
Too Hot a Topic?
No, it serves entirely as an opportunity to differentiate yourself professionally in your marketplace by declaring your values and attracting other professionals of like values to work with, as well as customers who want it your way. You do not want to attract everyone, so choose those with whom you can work well, and start a dialogue.
Recently, I helped a client of mine do this. He decided it was more important to other advisers how they were paid. It made little difference to my client how they were paid, as long as it was within the law and full disclosure was made to the client. He is interested in working on cases with competent, ethical, intelligent professionals of various disciplines and forming teams that work together amicably for the benefit of the client. He also wanted to be recognized by those teams as the competent, ethical, and intelligent participant that he is. In other words, as a full and equal participant.