Really - why’s that then ? Could it be because of insurance / liability ?? 
A neighbour helping a neighbour is one thing, paying someone is something else. Everyone around here has a chainsaw but very few would climb a tree with one.
Geoff… I apologise if I have wasted your time…
As your posts progressed, I thought your major concern was to ensure that whoever helped you would be covered by Insurance in event of an accident.
This is why I suggested you discuss the situation with your Insurance Company.
However, it is absolutely true that chainsaws are dangerous tools and that you might be better served by getting a Professional in to do the work.
Only you can see what the work entails and make a judgement.
Best of luck…
They are a crazy lot in these parts…
When we were first over here, I used to send photos back to the H&S guys for them to use in training sessions "how NOT to do… "