Twins in squash (cell division)

So, I've been perusing my local produce section the past couple weeks to see if they add more squash to the pile. I've noticed by now,  that there have been 3 different fruits that appear to be twins as in two conjoined fruit that share the same stem. One was a delicata, & the other two were acorn types called sweet dumpling.  This seems like it would be an uncommon occurrence,  but with these numbers it's like 1 in 12ish.  Is this a fairly frequent thing with squash?  If one were to save seeds, are double fruit likely to replicate that trait?  I wouldn't think so, but then again,  I'm just getting into winter squash.