He didn't ask for "better offensively" or "better defensively," he asked for "better." So take every aspect of the player and find who is overall the better hockey player.
It's been the same for this entire poll series, BBA.
You still aren't answering a very basic question. "Better" is a very subjective term, particularly when comparing players that play different positions and I'm simply trying to get clarification to make it less subjective. Staal will very likely be measurably better defensively, a better possession player, face tougher competition and is a center. Guentzel will very likely be measurably superior offensively. So for example, if Guentzel scores 60 points playing on a top line and PP and Staal plays as a center against the toughest competition and is outstanding defensively and scores 50, who is "better" and why?
More simply put, what level of scoring advantage would Guentzel need to achieve to overcome the fact that Staal is a center and will likely be superior in many other aspects of the game?
Is 5 points enough? Is 10? is 15? Is 20?
Simple question. Easy to say "Just better based on all aspects", but it's meaningless without explaining what one means.