QuickBooks Online (QBO) lets you create a personalized and professional-looking estimates. However, assigning specific templates to individual sales people is unavailable. I have a tip on what you can about this, fairfieldinnovations.
You can create an estimate and customize the template for for each salesperson by providing their phone number, email, and other details in relevant fields. And yes you're right, any changes to one template is set to automatically adjust the others. To do so, follow the steps below:
- Go to the Gear icon and select Custom form styles.
- Click New style, then Estimate.
- Under Design, in the Change up the template section choose a template .

- Navigate to the Content tab, provide the details of the sales person. You can click the which part of the invoice you want it to be added.

- Click Done.
Repeat the process for the other Sales person and make sure to save the templates with a descriptive name such as Estimate for Salesperson A and B to easily determine what template to select.
To know more on how to change the look and information of your forms that includes logo or address, check out this article for more information: Customize Invoices, Estimates, and Sales Receipts in QuickBooks Online.
After a customer accepts your estimates, you can convert this to invoice. I've got this for you: Convert An Estimate Into an Invoice.
Did you know that our QuickBooks Live Expert Assisted team is available on demand to help you make the most of your transactions? This ensures you always have a clear understanding of your business performance.
Let me know if you have any questions or concerns when creating estimates. I'm always here happy to assist you further. Have a nice day