Read the article again. This change will make it easier to mount a challenge, not more difficult. Whoever manages to win a caucus or primary will get the delegates. There will be no room for backroom maneuvering.
It means that big states and big money will monopolize the process. Nobody without a warchest of tens of millions of dollars BEFORE any primaries or caucuses will even get a sniff. No more early caucuses and primaries in small states to yield surprises.
On the other hand, it will force actual conservatives to form a new party if they want representation.