I don't think Blessing hit 90 mph on the dot...not yet at least. But he got damn close in the Ireland series (89.5 mph) or maybe a touch quicker. Its all decimals at that point. But that is quite rapid. Only Chatara, and Jarvis have bowled at that speed since the Rebels left in 2004. And I guess Chivanga the other day. I think the current ZIM seamers bowl as follows:
Blessing (145 top speed, 135 average)
Ngarava (140 top speed, 135 average)
Nyauchi (130 top speed, 125 average)
Jongwe (135 top speed, 125 average)
Haven't seen enough of Evans, Chivanga...but seems Evans bowls around 130, with a top of 135. I'd guess Chivanga averages 135-137 and maxes out around 145.