Fratantuono on Aeneid, Book Two

Fratantuono's commentary (Madness Unchained) has been good so far: unlike some other Aeneid commentaries I've looked at, he is everywhere concerned with the literary interpretation of the poem, bringing his considerable knowledge of the classical and Virgilian tradition to bear on the work's own inner trajectory. One small regret is that he does not spend any time trying to interpret the scene, early in Book Two, where the two Trojans, Capys and Thymoetes, argue about whether the Horse ought to be brought within the walls of the city. I (with my small Latin and less Greek) have been inclined to interpret their names as etymological hints: "Capys," which seems to hint at caput--the head--is arguing against bringing the horse in, while "Thymoetes"--pretty clearly drawn from the Greek thumos, for spiritedness or heart--urges that the colossus be brought within the city walls. The heart wins out over the head and the thing happens, to their downfall. This interpretation seems to jive with the Aeneid's general emphasis on rational rule over spiritedness and the passions, but is there a more-than-apparent connection in the Latin? I'm not the one to ask...

Meanwhile I hear the voice of my old Greek professor echoing in my ears: "etymology by sound does not make for sound etymology."