Nor sure which 737 you are flying, eagle, but all the ones I fly (3/4/5/7) display a TMG in 'Expanded VOR' mode. We do not have a 'VOR' button' on the EFIS panel, mind you. We have a 'VOR/LOC' button which does not affect the EFIS display. We also use 'HDG' at the top for all modes. You must have a different system? It can almost certainly be changed by your company, as I said.