The mere existence of the object itself isn't a determining factor of what it's orbit would actually be - The orbit could be way different that what's being theorized at this time.
You also made the point for me by saying "Proposed Orbital Path" meaning this is still theoretical with nothing factual at this time to define it ...... All I'm saying here is we just don't have enough info (Yet) to declare anything as an absolute, we haven't even seen it yet to really know it's true size or anything.
In fact while it's very existence is still in question at this time, there is a great deal of evidence to support something really is out there but as to what this something is well... you know.
I mean we all know it's got to be a planet to have the effects that's been observed and measured.
Seriously, all we can do at this time is make our best guess with what limited info we do have, continue to watch and gather evidence.