Welcome to the Q&A Forum

This is actually more common than you might think, though you probably don't even realize it sometimes.  I've only seen this with forums, blogs, multi-language/geo sites, etc.. that are hosted with different technologies on different servers (Cart on IIS, Blog on LAMP, etc..) and the SEO/Dev team has agreed this is better than a subdomain path. The biggest challenge will likely be in ensuring the load times aren't affected, but this can generally be easily overcome by hosting the different servers in the same datacenter, caching elements on the master server, etc.. Cheers, Jake