Captain reported concerns over push back procedures that had his wing tip pass over the wing of a parked aircraft on an adjacent gate.

Narrative

Left on time; no time pressure. Called for normal push back. Cleared to push onto Taxiway XX; short of XY. Push crew pushed the plane straight back; not following the lead in line for the angled line. If you push straight back; the plane impinges on the safety space for the adjacent gate; XX. Half way into the push I noticed the plane not angling away from Gate XX. The left wing passed over the plane parked at Gate XX; an E-170. I am sure it was very close to hitting the vertical fin of the RJ. The wing walker on the L wing held up the wand the entire push. I very clearly informed the tractor driver of the impending disaster; he slowed a bit but continue the push. I tried to get him to stop but did not. After clearing the E-170 at Gate XX; I again very clearly told him of the error and potential for damage. He did not seem to know anything about the procedures for pushing a wide body from Gate XY.I have had numerous problems with ramp push and receipt procedures; all from Gate XY. Once again; extremely important to emphasize proper procedure or someone is going to get hurt.