Are you trying to prevent multiple checks in one branch from creating multiple assemblies for this branch? You can do this without changing the concurrency settings by setting some parameters in the VCS Trigger part of your build configuration. There is a parameter “Silent period”, which waits X seconds before assembling, in case several commits appear at once.
Here is a screenshot of the corresponding menu in TeamCity 8.x :

: - → . , . 1+. , , , , .