You are both overthinking it AND you shouldn't like his answer.

So, a properly done joint should be fine. And good workmanship would have him replacing the entire section.

There really is a thing called good workmanship. It's over and above what will technically "work".

Helpful. lol

There was a similar post where a contractor cut out copper drain line and used pieced in PVC and Fernco fittings. Technically it will work. It's absolutely BS workmanship though.

There really is a standard beyond "what will work".

If it takes extraordinary work to replace the entire line - that's one thing. You don't want to rip out a finished wall just to have two fewer joints. But a bunch of patchwork isn't great otherwise.

You are overthinking this. The plumber is correct; no "bs workmanship".

If it is really important to you, you can call another plumber and have him fix it your way.

With PEX you should have a lot less fittings than other you would have with copper, etc. I would not worry about a couple of unexpected extra ones.

On the general note, the fewer fittings or splices the better... As the repairs go, a splice is a splice 2 or 4 if it's done the right way they shouldn't fail.

In this situation, if he found one leak and fixed it before he found the 2nd leak, I can see him making repairs in both places. I'm sure if he knew of the 2nd leak within a short distance before he made the 1st repair, he would have replaced the entire piece.

I betcha' that is exactly what happened, Gn Builders. Who woulda' thunk that the sider could have found that one pipe two times. I would have done the same thing--found the leak, fixed it, turned the water back on and stood back, then seen the second leak and said 'Oh, ____'. To the person who installed the siding: "Bet you can't do that again."