FYI the TACFIRE-ATHS has been removed from the E and iirc the late D versions of the Apache it was obsolete back in 2005, it was a shitty system just from reading about it u can tell its useless.
the Kiowas dont or barely use the TACFIRE-ATHS and JVMF (Tactical internet) systems for whatever reason the Kiowas used comms to communicate with other assets and apaches this was explained by a Kiowa pilot in the Polychop server they just never or barely used the datalinks, the apaches used the JVMF system regularly, this is part of the reason why the Kiowa got retired, apache did its job better and more effectively, TACFIRE was Obsolete hence why it got removed from the Es, LINK16 replaced TACFIRE on the Echos, they still use JVMF and the AFAPD (longbow protocol).
THE JVMF can also call in Artillery using the FS protocol
A-10C2s had 0 Datalinks to share with the Apache, if u want to talk with a fixed wing u use comms this is with the D version of the apache, Echos like i said got LINK16 so they have an easier job sharing info with other aircraft that use LINK16
the Longbow Protocol Datalink isn't the JVMF (Tactical internet) its 2 Different Datalinks, ive heard from a Pilot that they used the JVMF when Radio silence is a thing so instead of using the Radio to talk with the other Apaches they use JVMF to send messages back and forth, it depends on the situation that u are in
LST, Smoke and Comms is what u should rely on when talking with other Fixed wing units