The 200Tdi has the advantage that the engine mounts and bell housing match the 2.25 - which simplifies things a bit. As commented above, the 200Tdi is simply a development of the 2.25, whereas the 300 is a redesign, among other points intended to make it so the same engine could be used in the Disco and Defender, not requiring two versions as was the case with the 200.
John

