Are you a real biologist? The biggest strongest rams ARE the number one breeders. Do they do ALL the breeding? No. There are many biological scenarios where that takes place. In this situation those inferior breeding rams are most likely "cheaters". That doesn't negate the fact that the biggest and strongest are...well, the biggest and strongest. According to evolution, the ewes would be insane to not want to breed with those rams, since they spend so many resources rearing offspring. Hence, they want to rear the top males offspring and not the lesser male's offspring.
Back to you temperature hold up. You are talking a half of a degree, not 20 degrees. Of course ocean and land environments aren't the same, but my point is as YOUR article is wrong in that temperature is the number one driving force if a "growing season", it is and remains daylight duration. Is temperature an important variable? Absolutely, but your hypothesis is flawed.