The phrase "a far less powerful" is correct and usable in written English.
It can be used to compare the power or effectiveness of two entities, indicating that one is significantly weaker than the other.
Example: "In this context, the new engine is a far less powerful option compared to the previous model."
Alternatives: "much weaker" or "significantly less potent".
Medicare cuts are a political loser, but Medicaid — serving a far less powerful clientele than the middle class — has become highly vulnerable to their ax.
Pyongyang claimed it had tested a hydrogen bomb for the first time, but experts believe that residual evidence and the size of the seismic shock point to a far less powerful device.
The Camry's got 208 horses under its hood; the Prius' engine has a far less powerful 121 HP, and achieves zero-60 in an incredibly tepid 10 seconds.
But Arnott's statistical tests indicated that the natural tendency of good earnings to follow bad was a far less powerful predictor of ten-year earnings growth than the payout ratio itself.
It's a powerful man trying to diminish a far less powerful woman.
High-efficiency internal combustion engines, electric engines, or hybrid engines that combine the two are all far less powerful than conventional engines and will achieve a comparable level of performance only with a much lighter vehicle.
After all, a story identical to that experienced by every other player of a game is far less powerful than one that is unique to the individual, and, crucially, is more likely to be passed on to others and shared.
The office of the president is a largely ceremonial one in Germany, far less powerful than the chancellor's.
Those who have experimented with the modified device say it is equivalent to a 150-megahertz Pentium machine -- far less powerful than most PC's being shipped today but with its modem and LCD screen still a bargain.
The sad fact is they may not work for everyone and they may be far less powerful than a well-designed drug.
