That would be minimum for 720p right there and the Vega 10 GPU is orders of magnitude faster than the Intel HD 4000.
Intel's HD 4000 is definitely not going to be the minimum for playable 720p. I sometimes play on a notebook with integrated HD 6000 graphics, and still have to turn the render scaling down to keep things playable on that system. Think more like 360p, with framerates under 60fps. : D
Checking a couple quick videos on Youtube tells me a 2400G with its integrated Vega 11 graphics should be decent at maintaining framerates over 60fps at 720p with reduced settings, but don't expect over 100fps. If you want to maintain 120fps, you'll need a dedicated graphics card and possibly a bit faster CPU as well.
Also, do you have a high refresh rate monitor already? And how much was the maximum budget for this setup? Do you happen to have an existing system that might be worth upgrading?