Adepts can stack a crazy amount of dice if they try. +2 from Shark Totem, +3 from Improved Ability, + Agility Boost, + Weapon Foci (shock gloves, knucks, whatever), ect, ect.
You can increase DV from Critical Strike power, using the called shot rules, and/or the mentioned Shock Gloves, Knucks, or the assorted Metahuman options to bump Str.
Yes, you're still short DV compared to an Orc with Bone and Str augments, but you've got more dice. And if you're in a long campaign, Magic "beats" Augments. And most physical Adepts have a Magic priority B compared to a Samurai's A in Resources so the Adept character picks up something, somewhere, usually mental stats.
I would argue that DV 13 with 17 Dice, vs. DV 10 with 21 Dice are close 'nuff in effectiveness. (Numbers are pulled from memory of theorycrafted builds, I'm willing to be off a bit).