AH-94 Radar range

Is there a reason why the radar on the AH-94 only goes out 8 miles? I think i would be alot happier with 12 or even 16 miles. I understand that 8 miles is the longest possible stand-still ground kill you can get with the 145 and the 114 but it would give quite a bit of situaltional awareness being able to lock something up with the radar at a longer range and slaving the TADS to it.

Does ground radar have overall weaker performance compaired to air radar IRL?