I am a project manager and I use MS Project to manage multiple projects. I use a shared resource pool. I have been playing with the charts feature, in the resource file to try to get a chart showing a stacked bar chart (not 100%) showing project by person for a certain time frame.
There are tools that exist that that can produce the kind of charts you are trying to create from MS Project. Here's one
You should know that using shared resource pools in MS Project can be very dangerous. In the words of Rod Gill (MS Project expert and Microsoft MVP):
WARNING: linked files are VERY susceptible to file corruption. If you ever rename, move, overwrite or save teh files on a WAN you roll the file corruption dice. It's a matter of when not if one or more files corrupt. If you do need to rename or move files first break the links to teh mater and resource pool, save all files, do what you need then re-link. Explore using unlinked master files that consolidate resource workloads for reporting purposes instead.