Mental classes in D20 Modern?

[Spatula]

I have to disagree. A low-level Modern characters owns a low-level DnD character, if they're not a spellcaster. For instance, a Charismatic can pull off the same king of benefits as a bard (even faster at the lower levels) without spending slots. A low-level Strong or Strong/Soldier can quickly out-damage a fighter. (Strong 3/Soldier 2 gives you +4 damage before Strength modifiers!)

The advantage of D&D characters vs Modern ones is front-loading. A 1st level human fighter is proficient with all simple weapons, all martial weapons, all armor, and all shields. The character also has 2 general feats and 1 fighter feat. A 1st level human strong hero is proficient with all simple weapons and gets a strong talent, 2 general feats, and possibly a feat from background. The fighter also has more hit points. In this case, the D&D character has an obvious advantage over the Modern character.

As the characters advance, they both get bonus feats, but the fighter has a massively flexible list to choose bonus feats from while the strong hero (or any other Modern class) does not. The strong hero's bonus melee damage from Melee Smash talents doesn't make up for all the other advantages the fighter started out with. Your Strong 3/Soldier 2 has a lower BAB and is either going to have a lower AC or have less tactical options in combat vs. a Fighter 5.