I think the bigger issue is money. Hillary Clinton is being subsidized by multiple banks and individual billionaires. Bernie Sanders, unfortunately, can't hire people of the same caliber or vet candidates as extensively.
This is laughable. People put together competent campaign staffs all the time without major money. McCain had a pretty good staff in 2007 (still amazed he survived to get the nomination), as did Obama before the money started piling in. Santorum had a nice small staff in 2012. Even Ron Paul had competent campaign people who put him in position to do decently in caucuses and primaries.
Sanders has surrounded himself with amateurs. Unlike Obama, who was a community organizer and rose up to the Chicago political machine, Sanders has no experience in this game and hasn't surrounded himself with competent staff members in leadership positions. Which is how you end up with a shit show like that press conference. It has nothing to do with money, which he has plenty of btw.
He's running an aimless campaign, doesn't know how to spend his money, and is going to get crushed the minute the primaries move to browner states.