For your intended use your .300 Win Mag should work.
I will add that 30 some years ago i shot 3 rifles to check zero for some older guys. A .300 H&H, a .300 Win Mag Ruger 77, and a Mark V .300 Weatherby with a light 24" barrel.
The first two were a joy to shoot.
The lightweight Weatherby kicked the s$&%t out of me, literally picking my torso up off of the bench. I shot it twice and called it good!
Conclusion to me was that a light weight .300 Weatherby was not fun to shoot.
Each person will apply their own law of diminishing return to your question.
I don't think that you will see a significant increase in field performance with the higher velocity of the weatherby.
