As much as it seems like these guys are years apart, Blake is almost exactly one year older than Hayward (28 vs 27) and has been in the league exactly one year longer (2009 vs 2010). BUT Blake had a "redshirt" rookie season with injury. Blake still may well have the higher odometer, plus the longer injury checklist. Those are problematic.
However, Blake is also the better, more complete player, when both are healthy. Last season their PPG was about the same, while Griffin had higher assist and rebound per game rates.
Not to mention - Jaylen Brown could end up having a really nice Year 2, while Jae (though I can't stand watching him) is still a valuable guy with good +/- numbers and strong defense. AND, there are always strong trade candidates at the 3 spot (PG, Butler) throughout the year.