Like any scheme, it depends on the personnel. If you can find a monster NT and some good rush OLBs, it will be very successful. Stanford's D is a 3-4 two gap D. A lot of Ds have been successful with this system. It's all about finding the pieces. It may or may not be a great cultural fit for SF athletes, but the scheme itself isn't incapable of being successful.
It is not just cultural, there is a climate element. The 3-4 you speak of requires huge NTs and much bigger dline and LBs than normally exist down here. Our old teams were always smaller--even on Oline, so where the Dolphins when they were great. Hot, humid, makes it difficult to be an active, aggressive type of person if you carry those extra pounds. Those big players from other teams us to collapse in So FL humidity and heat. That is one reason we owned the fourth quarter. Now our guys collapse in the 4th and at end of season.
We have been witness to two of the greatest examples of football in history down here and both took place with smaller quicker players than their opposition. And it is not about black inner city kids; the undefeated Dolphins started 10 out 11 white dudes on defense and numerous white guy on offense. All were smaller than their counterparts in the NFL, except Zonk. We have an example of the greatest pro team and perhaps the great college dynasty, why not follow them. Caution, both these played in the OB, with probably the fastest turf in the country -- now both play in a cow pasture in north Dade. Small and really fast is good; small and slower, is not.