One is a legend who fought Roger and Garp while the other is fodder capped at Snack
Here, I'll summarize the differences for you:
—Dressrosa was the arc that both introduced Chinjao and gave him a transcendent role in the plot. Urouge is still to be developed in the main story, after which he may or may not follow Chinjao's change of mind (if Urouge is indeed linked to Blackbeard).
—Urouge is part of the Worst Generation, whose members have been used by Oda to spice arcs up through the New World. It's not my problem that people are so impatient and know so little about how writing works that they expect Oda to throw every member at the first arc; funnily enough, the only members who haven't received consistent focus in the current plot yet are Blackbeard and Urouge, so of course Urouge showing interest in Teach is something to think about, at least.
—So far every Supernova has made a bigger impact in the overall story than Chinjao, so no point in comparing them.
But surely I'm the idiot instead of the guy focusing on the similarities instead of the differences.