Arky

I think injury chances for the 0 and 1 cards are priced steeply in some cases, and also discounted on some cards for the <600 PA guys or the 2s and worse.

If it's the right value and the right cap, and I've made lineup options, I would never hesitate to use a 1 injury card (<600PA).
In Arky's case, he is a unique animal as a power lefty SS, and his card maybe isn't as good a value as Wagner, but not many are. I don't find it overpriced and SS is an easy position to cover economically with a 2 range glove.

IMO, a lot of managers overemphasize the downside risk, but what about the upside risk?

On those happy occasions when your stud 15-game injury risk player plays in all 162 games, your team will dominate. A second scenario is when key players are frequently out of the lineup during regular season, but you sneak into postseason anyway. If the 15-game injury guys stay healthy in postseason, you have a much more powerful playoff team.