We currently have two feature teams, one Web one mobile. They have their own backlogs. Each have their own product manager and scrum master. Team size is 11 including scrum and product role per team.
We have an increasing demand for delivery outside of the product backlog from other projects. Some will touch Web, some will touch mobile and some will touch both.
We've proposed a 3rd team, who will be capable of working on Web and Mobile delivery from demand outside the existing backlog. In times of slack they will help the existing feature teams with their backlog.
However one lead is stating the CI/CD overhead will be too much and instead of creating a 3rd team, we should bolster the existing team sizes, which is against textbook.
I'm personally against this as I believe the existing product backlogs will also be pernially pushed back because the external demand will be of a higher priority.
Thoughts on how to proceed?