Everyone is here to help, not to misleading. The letter from the employer is never save. That's why there are "incorrect wording" and "we put together the templates". The official, or governmental documents are much saver to prove the hours and payments. But the problem is that some of us do not have enough working hours with taxable income shown on these files. In CEC and FSW categories, work with non-taxable income and an employment letter saying "the applicant actually works more hours" will never work. In our stream, you can play with the wording and try your luck. That's why the letter from the employer is the only thing to relay on for some of us.
In terms of duty, for sure you need the letter with details just like in your templates.
What I was suggested is: if someone has sufficient hours with taxable income, then provide T4/NOA/pay stubs/contracts. Otherwise, these documents will be inconsistent with the arbitrary hours claimed in the employer letter thus should not be included. Consistency of the supporting documents should be the first principle for all the files in one's package.