This is is just a reordering on the pipes and the rational about it.

Due to limitations on the buffering of pipes and therefore possible
resulting deadlocks, the order the pipes are read is crucial.
The reordering (STDOUT before STDERR) will not(!) prevent a deadlock, if the
output of the process to STDERR exceeds the max buffered size on STDERR.

Better handle the unlikely error, than get stuck on the goods.