My point is that the very concept of an interstellar resource war, and thus the concept of interstellar control, is incoherent given our present physics. You can take over a system that isn't technologically enabled, but that's it, the resources available to a technologically enabled system are greater than the resources that can be sent into the system.
So it's certainly feasible for an advanced race to build a star empire; the question is why they'd want to do it. If we're talking about humans you might say ambition or imagination. If Vulcans, maybe they'd think it logical to pre-emptively become stronger than any potential aggressors.
You could slam a bunch of mass into a system at extreme speeds, but then they just have to hop into life boats until the storm ends (if they have the capacity to ponder traveling the stars, they have the capacity to spend a decade on a space station).