My press teams all have just 4...I rotate them all through at the C position and then the 3 non-starters plus my top rebounding SF-type player (or, barring that, a high-ATH, high-DEF type) gets the 4 slot as PF to take a few minutes as needed. It gets some fatigue issues in uptempo vs. uptempo games, and if there's an injury to one of the four or a bad foul run early in the game, it can go loco pretty quick. But other than that, as long as 2 of the 4 have stamina in the low/mid 80s, you'll be in fine shape.