couple of reasons that lacrosse is the best "second sport" and preferable to basketball:
1) it's a contact sport. anytime you need to put on a helmet to play, it helps with football because you not only have to hit, but keep your athletic movements when being hit. compare that to getting ***** slapped on the wrist when making a layup and a ref yells "foul"
2) in order to play the sport, you need to learn to be perfectly ambidextrous, this has significant benefits for balance and coordination. imagine a pitcher being able to throw an 90 mph fastball over the outside corner of the plate as both a righty and lefty, you'll get what i mean.
3) you need to be able to throw the ball and catch with precision on a dead run, sprinting at full speed. in order to do that, you need to train your body to run with your hips almost perfectly level. think of the body control/precision that goes into a golf swing. if you can't do that in lacrosse, you're going to be a shortstop that puts every throw to first into the dugout, or two rows up into the bleachers. being able to run with your hips level like that gives you speed, agility, bend, explosion, and often ... at a superior level.
case in point: the best RB in football history was jim brown. the guy tied for best WR in football history was paul warfield. (tied with jerry rice). what did brown and warfield have in common, besides uncanny moves on the football field? yep, they played lacrosse. which was how they learned to run like they did. not a coincidence in my view.
if i'm advising a kid that plays football, i tell them: play lacrosse