Some of the R&D guys are not overkeen on mixing sets - because they work so hard on getting the flow correct between the clubs - offset, trajectory ect.
However, it is an option we offer and as it started becoming more common place - the MP-62 and MP-52 were designed with this in mind.
If you're going for more feel and control in the shorter irons, you might as well go all the way and combine with the 62's rather than 57's. Then you really do have the correct tools at the right end of the bag.