I think Taylor was very, very wrong.
If someone is working multiple projects and there’s a clear time allocation given, then yes they’ll report to the different project managers, and any allocation or priority conflicts need to be worked out by the managers or perhaps a functional manager who really controls where staff is allocated.
But I don’t care how good the intentions are, any more than 1 manager unless absolutely necessary is a bad idea. Communication becomes conflicting, the tragedy of the commons rears it’s head when no single manager is responsible for the staff member, etc.
Every time I’ve seen it, it’s been a negative thing that’s had to either change or taken workarounds to manage. Like Jerry’s situation – it’s the best workaround in the circumstance, but better yet would be to avoid multiple managers.