10% or 20% fine from the match fees is a joke. If the ICC wants to make sure that the over rate is maintained, then they should penalize by either deducting runs from the side that is responsible for the delay, or award extra runs for the opposite side. Financial penalties have a disproportionately negative impact on smaller teams such as West Indies, while the bigger teams may chose to ignore it.
Cricketing world is divided on this matter and ICC is confused as far as i understand. ICC gets heat from experts when game lose the overs, Fees penalty is not working. they did ban Windies captain recently due to same reason and decision didn't go well. "Deducting runs" could work on some cases but its very controversial decision.
this is a good article
https://www.espncricinfo.com/story/_/id/25978697/breaches-bans-all-need-know-rate-offences
The way kiwis are playing, they might not able to witness full house in Aus anytime soon.