The sad state of ground rewards
Firstly, do not pay attention to the total rewards of a long sucessful match, what really matters are those rewards divided by your activity time, that will give you a better insight of how effective your grind is.
Here is an extreme example of a good arcade match. The difference in rewards per minute between arcade and RB is small overall, but it’s easier to get higher reward multipliers on kills in RB, in arcade you need 8 or 9 kills to get the 100% multiplier. Let me know which mode nets you better rewards/min.
In this match, I was using the M64 premium tank, without premium time. So a TT vehicle of the same BR with premium time active would be similar.
Rewards per minute:
Modification RP/min: 967 RP
SL/min: 13671 SL
Modification rewards are more consistent since vehicle research is affected by rank differences and daily bonus.
A decent average top-tier arcade match, no premium or boosters.
Modification RP/min: 365 RP
SL/min: 4505 SL
This means that to unlock a 410k rp tank, you would need around 18h of similar activity time, or around 235 matches to unlock the next tank, with premium it would be half that. Daily research bonus and booster usage will obviously help, but it’s still very slow.
A decent average top tier Air RB match, no premium or boosters.
Modification RP/min: 984 RP
SL/min: 5726 SL
The rewards in ground, especially the research rewards, are very poor, and with the increased difficulty to achieve the reward multipliers from multiple kills in ground compared to air, makes it even more difficult to get decent results.