Ontario commercial car insurance and out of province drivers license

Hi.

I have a small business in Ontario with a commercial license vehicle.
My brother who is residing out of province (Alberta) who came to Ontario temporary to help out with business.

I am trying to add him to insurance (Gore Mutual) however they're telling me it's impossible, and it's a general rule/law across Canada.

Underwriter is telling me he has to have Ontario license in order to be added as a driver.

Does this sound about right?

Can't get Ontario license either since he's here temp for about a month.

Any other suggestions?

TIA