In your case, if it helps to set the cpu affinity and put programs to another core, i should do it.
Technicly pinafginity is not a magic tool that reduces the cpu, it only can put a process, to another (or multiple) cores.
By default a program will run and windows will decide on which core ot should run. Thats in most cases fine.
In my IT life I found that running a lot of scanning agent run on a server, could bring the cpu down. When adding 45 user to it, the server gets bumped to 100%cpu.
When putting all the scan agents to (for example) core 1, it had cores left to respond to users request.
This means for my end user the server was responding, but the core with all the security scan software was at 100% all day (if you have 8 core setver, it means just 12,5% cpu utilization).
My security team wasn't happy, as their tooling wasn't working as it should.
With this story, I hope you get my point. By moving programs to another core and releasing cpu resources, other programs must get into trouble.
If it is working on an end user side for you, don't bother and use it.