Thats not what drop 2 means. If bari is playing drop 2 voicing, 2nd alto will play a different note. There is no doubling of notes. It's just that the 2nd voice drops an octave and ends up in the bari part.Great stuff, Saxhound. For bari though, I think it's more common that they're doubling the 2nd alto an octave down, 'drop 2', with some note differences here and there. That's my choice, personally, I rarely or never double the lead.
Med Flory of Supersax fame wrote nearly all his solis with the bari doubling lead alto. Just a different approach you might see on occasion.