Sourdough starters with different smells - is this normal?
One is on the heat pad and the other is...where?  Different temps will facilitate the growth of different yeast and bacteria.  Also, your kit is likely populated with different micro flora than the starter you created.  Finally, which "smell" would you rather use to bake bread?  I would go with yeasty.  Starters get acidic fairly quickly.  This inhibits the growth of micro flora.  That is why feeding requires you to remove a significant amount before replenishing.  If you want to play, remove most of the "stomach-acid" starter, and feed the rest with flour and water (maybe remove it from the heating pad as an experiment...or try two small versions...on on and one off).  Build up again, and see if you can achieve a more pleasant aroma.