There are a lot of variables in the wood and how a bass ends up sounding. Identical construction can sure end up sounding different. I was an Alverez dealer back in the 80's and I had two acoustics that were identical and these two guitars could not have sounded more different from each other than anything I ever heard.
Builders like Mike Tobias certainly hold a world of knowledge and can control things to a certain extent but there still is that variable of the wood and then add that to combinations of woods and you get an exponential increase in part of the process being a bit of a crap shoot. Though I doubt very seriously Mr. Tobias has made a dud in many years but he may have made some instruments that some like over others. We all have different tastes too. Back in the 70's,and 80's there was still quite a bit of experimentation going on as I'm sure there is today, the variables are endless.
I am a firm believer in how different woods react and sound both sonically, sustain, timbre, and percussiveness. Add to that variables in the same wood with increased variables in the combinations and there is quite a large amount of differing characteristics to be had out there in Bassdom.
Mike is definitely a wood master. On his "flagship models" like the Andrew Gouche and Norm Stockton, Mike told me that he goes a few extra steps to ensure consistency. Part of the is the titanium rods in the neck. The other is in the woods he chooses. He purposely will use body and top woods that are from the same batch, if possible. And he also checks the density of those woods and keeps them same. So, in theory, each one will come out sounding as close to the same as possible. As already noted, it's still wood. But, most people are not going to be able to hear the difference.