My 20+ year old Carrier 2 1/2 ton Hp has a compressor failure.

I woul like to swap a trane XR12 2 1/2 ton HP and keep the existing indoor coil, which is in good shape.

Use all other existing tsat, lines would remain.

Contractor wants to put in matching coil.

I know that he is right to maximize the system, but will the system function fairly well without a new coil?

Is this a minefield that I do not want to enter?