Packets with fake source address can easily be spotted, and will raise an alert. In terms of using multiple interfaces for a single service it might be easy to hack together in a python script, but last time I checked the linux kernel support for bundling multiple interfaces is limited to redundancy and failover.

What I'd like to have is a single service dynamically using many network interfaces with randomized packet timings and randomized packet scheduling (5 packets on first interface, pause on 2nd, some on third interface, sometimes send traffic simultaneously).