When the RVR at LPL, is still below limits, the clock is ticking and the passengers at both ends are backing up and it's a Friday. It is a wise move to get another aircraft in when the WX improves that can take 2 ATR loads at a time because if you don't the clock will beat you as the airport on the IOM has to close.
So a 737 was the right choice and with a double load makes financial sense.
EMX have improved and learned from the past to look after the customers when things go wrong.
There is a lack of wet lease aircraft out there and having a spares for small fleet is too expensive.