The council should have voted on the Clerks employment contract, so in the minutes, somewhere there should be a blank contract available to view even if it has no names attached, it will give you a fair overview.
Most Parish Councils usually follow the CALC or NALC templates for contract of employment.
It may be a case of working smarter not longer - ask to do a review of their workload but it needs to be in an aim to help them not hinder. It could be that the clerk is being pulled in many directions on different sides which is consuming their time.
Some Councillors, not all, "always asks the clerk" so the clerk does the work, when the councillor themselves can do a little research and find the answer they are looking for.