If the 175 is only to operate MAN and BHX then that seems like a massive under utilisation of an airframe.
If they were operating once a day to each destination then maybe but I'm pretty sure that the aircraft will be fully utilised. Bearing in mind that the average length of each flight (BHX & MAN) will reduce compared to LGW, I think that utilisation may even improve as the Embraer that did 6 flights per day, can now do 8.