Zendesk and Phone System Integration

Has anyone got any experience of using Zendesk Talk alongside another phone solution (i.e. the support team using Zendesk Talk, but the rest of a business using Teams for phone calls). We are looking at doing something but for the sake of about 5 phones on talk, the rest needs to be on normal phones and we don’t want to have to get everyone that needs to make a phone call a zendesk talk licence.

Thanks!