Chase = Winner
Well, actually, I won. ;-)
I did behave myself, sort of. Randi put all his models on the table while I was still putting together my list. He was playing all short range units, avengers, avengers, guardians, farseer and scorpions. I was tempted to switch in a squad of reapers to get a decisive range advantage...
Instead, I stuck with my original concept... avengers, avengers, farseer and warp spiders. The result was a maneuver fight, where everyone had short ranged stuff. The speed of the spiders was very helpful in letting me engage two or three of my units in a given turn while he was spread out and slow enough that he could only engage one or two of his units. Randi's major advantage was the scorpion's ability in close combat, so the first thing I did was shoot the scorpions, to eliminate his major advantage without letting the scorpions close to melee.
Part of the game is to create mismatches, to have units that can do a lot of damage while not getting hurt badly. Part of it is in maneuver. If one has an advantage in range, in speed, or in close combat, one has to manage the game so as to take advantage of one's advantages. I'm with Chase in that winning through unit selection can be over done.