It's differences in wave timing and separation. Chance of 2 storms that hit that same areas in the 1/6-1/10 arent great, just mho.
What the ensembles are showing as 2 diff storms are actually: an earlier storm around the 6-7th with the followup being shunted s and e behind the 500mb flow out of the NW...or slower shortwave that has more time to dig as the NAO ridge retrogrades to Davis Strait and creates a euro-type situation centered around the 9th...thus is appears on the smoothed ens means as 2 different back to back storms when in reality they are unclear exactly which of the 2 waves to develop. I mean, my take could be 100% wrong....Feb 2010 happened.
Not sure we should be rooting for 1 over the other. We likely get a shot at a bigger storm later as the pattern relaxes/reloads...at least that's how these telleconnections have worked in the past.