My take on this situation is a little different. To me, you take a 3-0 pitch in a close game because the pitcher is having trouble finding the strike zone and you want him to work for an out. In a lop-sided game, swing away. Cave is likely to get a hit about once in four tries so the odds are in Texas' favor if he swings.As for "unwritten rules", write them down so everyone knows what they are. Or if they are too embarrassing to write down, get rid of them.
Minor point. He's going to get a hit a lot more than 25% of the time on a 3-0 count, especially when he knows a bp meatball is coming down the middle of the plate.
His career sample size on 3-0 is too small to cite, but he's a career .378 hitter when ahead in the count. In that situation it's going to be a hit probably 60+ % of the time.