I have actually seen the opposite, as the Rhino's peeter out. The BC LINK consistantly can be heard by the rhinos, but the rhinos cannot be heard by the BC LINK or very static when the distances increase. This is especially true with the previous generation rhino. i have talked BC LINK- BC LINK over 4 miles through mountain timber, which i think is very impressive.
These 2 way radios are 2 radios in one. Each is a transmitter and a reciever that use the same antenna. Reciever sensitivity and antenna efficiency have as much effect on range as tx power. Maybe more. When recieving a weak signal, moving a few feet in any direction will change the signal strength. I have raised a radio an arms length overhead and the signal went from unintelligible to full quieting. The fcc type accepted radios are all made to a set of fcc specs/rules. Those rules are a one size fits all thing that works well for in town on-site comms. Doesnt work so well for casual rural recreational comms. Unless you understand the rules and work them to you advantage.
The frs/gmrs combo units usually have 22 channels. 1 - 14 are frs, no license. 15 - 22 are gmrs, license reqired. 50 watt limit, no limit on antenna gain. (License is $65 for five years, covers your whole family out to cousins.) 1 - 7 are shared with gmrs, 5 watts for licensed gmrs users.
Frs is .5 watts, no removable antennas, no license. No one or very few care about the fcc rules. However, the fines are usually horrendous, in the 10s of thousands. You can take your chances.
Where I'm going.... there is equipment that is more capable than the fcc type accepted stuff.(garmin bca ect). If you want better more reliable comms in the backcountry. You will need to ask some questions. Google is your friend. Read some then some more. There is a fair amount of info on this forum. U just need to find and read.
Here are some things to look at.
wiki ctcss, frs, gmrs, frs frequency list, gmrs freqency list, vhf, uhf
amazon, baofeng bf888, ftdi programming cable, speaker mic,
Miklor.com
My advice is that u use only frs/gmrs/murs frequencies. Follow the kiss rule. Be very careful not to cause interference to other users. Above all, stay off of law enforcement/ems/qovt frequencies!