Adoption is not a training problem. It is a design problem that shows up three weeks after go-live, once the novelty wears off.
The week-three drop
Usage after go-live usually looks healthy for a fortnight. Then it falls. The cause is rarely resistance to change, it is that the system asks for more effort than it returns.
If a rep updates eight fields and gets nothing back, they stop. If updating those fields produces a forecast their manager uses instead of a spreadsheet chase, they continue.
Cut the required fields hard
Every required field is a tax on every record. Keep only the ones that drive a report or an automation, and remove the rest, you can always add them back with a reason attached.
Make the system give something back
Automated follow-up tasks, pre-filled quote documents, one-click logging from the inbox, a pipeline view that replaces the weekly spreadsheet. Visible returns for the data entered are what sustain adoption.
Manage from the CRM, publicly
Adoption follows leadership behaviour. If pipeline reviews run from the CRM dashboard and nowhere else, the data gets accurate quickly. If managers still accept a spreadsheet, the CRM becomes optional overhead.