You bring up a good point that rhinos are near completely useless. To logically chose them over wagners you would have to be hurting for energy or in some scenario where their slightly increased hp/mass ratio is desirable over speed, better aiming, and higher, frontloaded dps. Wagners are better in virtually every way (yes they have -1 range), and beat rhinos mass for mass. This is ridiculous.
But, a speed bonus does not fix rhinos, and the other faction's units are all useful as is.
ColonelSheppard wrote:T2 raiding troops are already effective enough.
^