Dynamic image selection for cloud support

I am experimenting with using the cloud support (currently using the docker plugin but also experimenting with VMWare)

If i have multiple images configured (eg one windows build agent image and one linux image) what is the expected behaviour if a build is scheduled and no images are currently running that meet that builds requirements but therer are idle agents.

eg if i only had 3 licenses, if i schedule 3 builds that required a linux agent i would see 3 linux images spun up to run those builds. if i then scheduled a windows build, would it terminate one the linux agents once it is idle to allow for a windows agent to start or would i have to wait for of the linux agents idle time to expire?

thanks