It's definitely a short bench, but that's what happens when you move 6 players at/around the trade deadline (I'm counting the Hernangomez deal and the later deal sending Dozier+Bol to the Magic as one deal since those two basically weren't on the team). If a good buyout player had been available, maybe that would have helped, but we weren't really viewed as a contender until later so it's unlikely that they would have wanted to sign with us.
You don't usually see contenders trading that many players at the deadline, so it's hard to compare the current depth to other contenders. It's something that will be a concern if it carries into next year, but the deep bench is typically something you take care of during the summer so that's what I'd expect anyway. If you're expecting the 12-15th men to be anything other than net negatives on the court, though, you're going to be disappointed. Good players don't sign on to be break-in-case-of-emergency depth.