As one can see from the table, "default" and "less" is actually the same setting. The "More" setting adds up to 2 attacks per season, while the "Lots" setting ups that to 3 attacks per season, which includes both winter and summer. Note that even on the final setting, Deerclops will still despawn once summer starts (but not when winter starts) - meaning any Deerclops spawned during summer won't actually despawn until the next summer begins on that setting!