Re: Formal correspondence introduction
Hi and welcome to Using English.
I can't say I find this very natural. Of course, it's a hard thing to do in a letter. You really can't say "X, meet Y" in written correspondence.
Perhaps something like:
I believe direct communication between the two of you could be more efficient at times, so I'd like this letter to serve as an introduction of sorts.
Bob, as you know, I'm John's pesonal assistant. You are welcome to work directly with John, though of course I remain ready to assist in any way I can.
John, Bob is Robbie's manager.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.