Whopity
That's how almost all light aircraft are rigged, one VOR/ILS antenna that is split at some place under the instrument panel to feed two VOR/LOC and GS boxes.
The latest Garmin split the VOR/ILS signal inside the box.
Mathematicly an antenna and length of coax cable is so reliable that failure is almost unheard of and far less likely than two independent failures inside the boxes.