explaining a decent RoS clause to client

I am trying to negotiate a new contract with a client, but their 'legal dept' are not following my explanation of my objections to their RoS clause.

The clause they propose is:

The Company has the right to substitute another representative of the Company to provide the Services to the Client provided that the Client consents in writing to the substitute and the proposed substitute possesses in the opinion of the Client and the Agent the necessary skills, expertise and resources to perform the Services.

I see this clause as having a client veto over the substitute and therefore seriously weakening it.

so I proposed the following one:

The Company shall have the right to supply one or more substitutes of equivalent expertise to work in place of the Consultant. The Company will ensure that the substitute has agreed to abide by the terms of this agreement.

However, their legal dept have objected to this on the grounds that it would allow me to send anyone without their agreement. I think this understanding is incorrect as the clause states that I can only send a sub with "equivalent expertise" and therefore I couldn't just send anybody.

What suitable explanation could I send to the client that explains the true nature & effect of my proposed RoS clause ( i.e. that I can only send a suitable sub ( with equiv expertise ), and if he isn't suitable then they can reject him/her ), and the problems with the original clause ( i.e. the effect of the client veto ).

-- squivy