No. A drafting service does not control immigration processing or establish eligibility.
Identify what the expense buys
Document preparation and actual permission are different events.
Separate the government charges for the chosen process from professional fees, document retrieval, any needed translation or credential evaluation, and travel, and confirm current amounts and what a professional quote actually includes before paying. The immigration side is inexpensive: a Canadian citizen may apply at a port of entry with the charge collected there, or an employer may file a petition carrying the fee shown in the current schedule, with premium processing available where timing is tight. The recurring components are advice on whether the change is material, preparation of the new agreement and support letter, and either a further presentation at a port of entry or an employer petition, with charges confirmed against the current published schedule. The larger spending usually sits elsewhere: an adviser's time reading the offer letter against the profession's rule, a credential evaluation if the degree was issued outside Canada, Mexico or the United States, and certified English translations for any document not already in English.