The upper and lower inlet manifolds are different on the 200, although all the late MK2 V6's and MK3 V6's, all had the bigger the lower inlet manifold fitted as standard. You can fit the upper inlet manifold as you have with no issue, and it will be an improvement, but you don't 'need' all the other improvements from the 200, but obviously they were designed to work together for the gains over the standard V6, so fitting everything is the way to get the best gains. Plenty of people have fitted just the upper inlet manifold to the standard V6.