RT needs INT
Rapid Trick removes preemptive strike and reduces speed. Some said it does not need INT in Ver C but I noticed INT does have an impact on the strength in reducing speed though removing preemptive strike does not need INT.
Some put RS and RT on the same mob which I think it is a waste. If your slower mob casts RS and RT before your enemy casts RS, your enemy RS will still take precedence. So removing preemptive strike in your RT becomes redundant thought it still have the effect of reducing speed.
So the most reliable way is have high speed for RS on a low INT mob since RS does not need INT and put RT on a high INT mob for the purpose of reducing speed if RS did not proc.
The preemptive strike in RT is only useful if you do not have RS. So having RT on both high speed + high INT mob become necessary in this case.