Hard to say from that link. I've started taking warmup a little more serious in the past 2 weeks and I think it makes a difference. I've make sure I hit some red-line efforts in the warmup, after 15-20 minutes of just getting the legs warm - for a long warmup like a race day at least. I think if you warm-up in terms of just riding around to get warm, you're still going to start cold when those guys up front go off at the gun. For me, I've found that I need at least 30 minutes with some high-end efforts thrown in.
I think it's much different for an enduro versus an XC race though.