I discussed this issue with Juno on OC this morning, the conversation in brief is as following :
Juno :If run more than 1 agent on same machine, they will affects each other..
It can be very difficult to find out the agent performance problem if user run multiple agents.
If one agent goes up to 100%, the other agent is also will be out of control.We can not control it.
If we can control process more, we can consider it..
DuBan : Let's consider this improvement in the future version. QA agree to postpone this issue to future version.