It would be radical to discard that possibility... I tend towards a bit of radicalism, generally, and on this matter, it has a possibility but only faint, for these reasons , which are not , of course, the be all end all. merely mine.
They liked to do things themselves.. paving, building, gardening, infrastructure, their own tax returns, car maintenance, Chris promoted himself as both mother and father, . and so on. They had each other, Chris and Paul. Hiring a third party, .. dangerous, and outside their square, if I may..
And they seemed to be both mean and extravagant at the same time. the outlay would have caused major pain, to Chris specifically, but also to Paul, who would have liked to undercut the bid for the job.
The thing about hitmen is,, they have a lifetime to live. One eventually has to knock off the hitman as he/she is a constant source of endless requests... it hardly ever is a one off payment. you just cannot buy that kind of life long loyalty, not with a one off payment.
Then there is the problem of having the hit man at your home, where your kids live.. either that, or lure your wife out of the home.. Remember Calasjik,, the hotel owner, got someone to shoot his wife in bed ,, while he was right next to her?.. didn't work out, as the shooter lost his mojo and wanted to blab.. you cant rely on anyone these days!...
One thing that is an unknown, is,, how many times, and by what method did Chris try and kill Lynn before he actually succeeded? Lynn never told a soul, and he won't, either, but I bet he did.