The 45 rule is good as a way to get most of the benefit but, although I couldn't tell how many decks Mr. Renzey was talking about in that article, or whether it was H17 or S17, the exception to that rule would be to hit all 6,6,4 from 1D thru 8D at least in S17 games.
As to your 4-card dilemma, in S17 games, hit A86A, A762, A663, 9322, 6622, & T222 for all decks 1 thru 8. Obviously AAA3 & AA22 are trivial.
Interestingly, probably only to me lol, one would stand on 9322 thru at least 4 decks.
Once again, not that this matters worth a cr*p, except to people like me suffering from OCD