A straight stock will produce less perceived recoil. This is because the line of recoil force is closer to the line of resistance so the gun or rifle does not rise up as much in recoil. Try shooting a Winchester M1894. The 30-30 is no thumper, but the M1894 will punish you more than my 400-360 becasue it has excess drop.

However, the choice is not driven by recoil considerations, but rather fit while aiming or pointing. The classic british double gun has a straight stock and splinter forend which causes the shooter to tend to shoot a bit higher, desirable when shooting at driven birds passing over head. (Coming in above the gun.) Guns with a pistol grip need to have a beavertail forend to compensate for the pistol grip, increasing the overall weight. For rough shooting (upland hunting here in the US.) the gun should follow the driven bird gun pattern or may have a slight pistol grip (Prince of Wales grip.) or a full pistol grip and a semi-beavertail forearm to cause the shooter to tend to shoot a bit lower.

In the case of the rifle, the game is "coming in under the gun" and so a pistol grip and splinter forearm are the order of the day. Fit is not quite as critical in the rifle since it is aimed instead of pointed like a gun. (Tell that to the guy who has something big and nasty coming at him fast.)

But each shooter is an individual, so he may find that breaking the rule works for him. I have seen a gun with grotesquely extreme cast off for a right handed shooter who was blind in the right eye.