66653
Radius on Arc Nades makes up for fitness deficiencies. Arc Nades are stupidly powerful but the real power of the kit is being able to effortlessly string together fire explosions and tech bursts. I only use Tac Scan for bosses BUT generally I only use my weapon for singles and bosses anyways. Also go radius on incinerate to not miss but not really as necessary if you open with arc nades anyways. Arc Pistol is pretty good on him, AP rounds, heavy barrel and power amp. Or you could go Lancer and incendiary cheese.
This .. 6 in Tac scan is actually pretty good, you can take area scan on the 6th evo, which will provide a tactical overlay of the enemy locations. Combining that with your super radius, hit things thru walls arc grenades, and you can maximize their effect by hitting as much as possible.
As NT says, arc grenades are also a great "oh Sh!t", get out of jail free card for a lower fitness build, as they stun everything in a wide radius