Getting Back to Papa Ogre's Weapon Ideas

The guy made some pretty good comments based on real weapon play that I really think should go into the game.

He said that secondary attacks are accurate but don't do as much damage as a primary attack.

I then came up with this idea.

All main and off-hand attack rolls get modifiers.

What if only main weapon or two-handed attacks that count as a main+off-hand action got damage modifiers?

All off-hand attacks get no damage modifiers.

The damage done would look something like this.

Level-Up Advancement Table
lvl 81 additional main action
lvl 151 additional off-hand action
lvl 221 additional reaction

small swordstr vs acoff-hand1d8
large swordstr vs acmain1d10+modifiers
two-handed swordstr vs acmain+off-hand3d6+modifiers

Your comments or suggestions?
Could you post the source that you are refering to please? Anyway, i don´t think 5e focuses on action economy, while i really like the action economy of 4e, i believe one movement and one action really helps to the speed of combats, and in doing this increasing the atention of the players to it. I´m not sure about giving this complexity to Next, at least to the core rules.