Its a recipe for failure if you insist on playing old school football, trying to always throw it deep (Al Davis), if you play a modern style offense like a spread hybrid west coast offense, you don't need a guy with a "big arm", which is a very OVERRATED aspect of playing qb. In terms of Lefevour, he has showed good velocity on the short and intermediate passes, and in the senior bowl threw 1 decent and 1 very good ball downfield, in a cold and somewhat windy environment.
I think most people here really overestimate how often the average team throws it downfield, and by that I mean the qb throws it 30 plus yards in the air. Last time I looked the av. 30+ yd/gm avg is about 2-4 times a game successfully, most ov the other long plays go around 15-25 yds, and the RAC gets the TD. I, for 1, am very anxious to see the combine to see all the Qb's throw all the routes, that is if the top 2 throw.