The most I can say is, it depends. Federal sentencing guidelines are interesting for a few reasons.
First, there is a formula which, quite literally, is a mathematical formula telling the judge a federal minimum and a federal maximum range of times for a crime. This is based on a number of data points surrounding the laws broken.
Second, each law has rules about its own sentencing guidelines baked in. Let's look at the specifics for Conspiracy for a Criminal Enterprise: 20 year minimum for first conviction, 30 year minimum for second conviction, a life sentence for a "extremely large enterprise". There are tables and figures for figuring out what all of this means for minimum to maximum and so on. I am not going to attempt to say I understand how this particular Federal judge will try to figure it out.
Third, in general sentences of multiple convictions on the same trial are supposed to be run concurrently. However, this can be changed if a court decides otherwise, for various reasons. Additionally it can be changed if a specific law states that it should not be run concurrently, but instead consecutively. The judge must actively consider whether to impose a concurrent or a consecutive sentence accounting to the US Code (18 US Code 3553 (a) [1]). Again I do not want to speak for a Federal judge but, I could easily see a judge interpreting these rules in this case to justify a consecutive instead of concurrent sentence.
I agree with you 100% that Mr. Ulbricht will likely not see the maximum consecutive sentence in this case. However, there are no hard and fast rules in Federal sentencing, they are guidelines. It could be decades, it could be quite a bit more.
[1] http://www.law.cornell.edu/uscode/text/18/3553#a