WIBC-HD2+107.5 is not the same program stream as WFNI+93.5. WFNI+93.5 appears to be their "primary" signal . It runs Mike & Mike and their slate of local hosts during the day, and NBC Sports Radio at night.
WIBC-HD2+107.5 runs the ESPN Radio feed all day, except for the hours Mike & Mike is on WFNI, when they sub in Erik Kuselius from NBC Sports Radio.
To recap the sports network wars in Indy:
ESPN Radio has 24-hour clearance on WFNI/WIBC-HD2
NBC Sports Radio now has 15 hour clearance in Indy (7pm to 10am), also via WFNI/WIBC-HD2
FOX Sports Radio has 17 hour clearance on WNDE+97.5
CBS Sports Radio has 23 hour clearance on WXNT (one hour in the early mornings is brokered colon cleanse)
Clearances obviously exclude local play-by-play.