Bad ideia to compare the manga (or anime) to the Web Novel.
The correct source is the Light Novel, wich is very different (in my oppinion - some will disagree) from the free Web Novel.
In the Web Novel the order of some events are different, but more important, there are more dialogues, but dialogues that totally destroy the characters, turning them more stupid, annoying or nonsense. The adaptation to Light Novel did the favor to remove these terrible content.
If you like Re:Zero, drop the Web Novel and read the Light Novel (it is available online at Amazon Kindle, actually at a cheap price for a japanese hyped series).