Attire of the groomsmen, fathers, and officiant. Opinions on vests?

I am trying to work out the details of the wedding party's attire to where the level of formality is cohesive throughout the wedding. My dress is more formal and detailed (A-line), and my fiance will be in a suit. To give some context, my wedding is taking place at 12 p.m. at a church in early March. There will be pretty decorations such as roses and a semi-formal buffet. I have the bridesmaids in short mismatched purple and pink styles ( I thought this would look simple and fun, but I still made sure the styles were on the formal side) and then I thought about having the groomsmen in vests and ties. This would match the bridesmaids' formality and save money. I have a couple of concerns, however. If the groomsmen wear vests, would it look weird if the fathers still wore suits? In other words, if one looked more formal than the other, should it be the fathers or the groomsmen? Also, would the pastor look weird if he wears his own suit but even the fathers are in vests ( if I decided to do it that way)? My alternative would be to put everyone in suits and hope it still matches the bridesmaids. Any advice is appreciated! If anyone has done vests before, please share your experience!