Maybe the wording should say, "Sacrifice up to 3 of your lowest attack creatures..." as if you have 3 creatures of equal attack, then all 3 are sacrificed, and added to your strongest 0|0 creature, or maybe they just all die, since the stats are added to nothing. The "up to" part means that you can sacrifice 2 creatures instead, allowing one creature to survive and receive the stats.
On a side note, since this is about culling the weak, are we going with the idea of low damage creatures, who are unable to provide much to the team, or should we go with current health, as the creature is "weak" as they are in poor health and are unable to pull their load.
On an even further side note, how would this interact with Antimatter, since the negative would subtract form the total attack boost added.
