If your question is, including scouting, what makes more EV... it's laughably Hole Carding, hands down.
It can vary a lot by region. In Vegas scouting efforts are much more efficient because of proximity of casinos. Could easily scout 20 plus casinos throughly in a day where as other parts of the country you might scout 3 casinos with long drives.
Holecarding is more fantasy than anything, at least at the shoe level. You would really need to find a sloppy dealer on exclusively pitch games and even then i find it hard to believe. If you do find a flasher, i doubt you can do it with any consistency.
This is what we want casinos to believe.
When we scout, ironically, CSMs are the best targets!
I've heard that and that's a lot more believable. I wouldnt be surprised if 6/5 tables were easy targets as well due to bosses putting inexperienced dealers on those games. I also am a bit sketpical of the randomness of these CSMs as well as ASMs, im sure you can probably sequence those. I tried it once on an ASM just watching from behind the table and the ace came out as expected. Sure it's anecdotal, but nonetheless i wouldnt be surprised and im sure CSMs are the same way.