Vandoren is a big name in reeds for all woodwind instruments. A reed is the piece of wood (cane, there are some plastic reeds on the market) you mount on a woodwind instrument mouthpiece with a ligature. The reed vibrates in the air expelled to produce sound.
There are many manufactures of reeds. Vandoren is the one heard by most parents because it is the most promoted reed/mouthpiece combo by band directors. Vandoren makes mouthpieces, but that's another review.
I have a teen in band. For years I've been hearing from her, "the director wants us to use this (or that)." I usually can convince her my ideas are better. The director is a brass man, while I played clarinet for centuries--not really but I'm dealing with a teen. The biggest issue was he wanted every woodwind in the band to be using Vandoren reeds.
I quit barking about it and gave in.
The Vandoren produces a fair bright sound. They do not produce as warm a tone as Mitchell Lurie reeds in my opinion. I suppose for a marching band they are looking for "bright" on the field.
For durability, these are reeds made from cane. They get wet; a moist reed actually plays better. They get knocked, bumped, and hastily applied so the tendency to split or chip is there with any reed, save the plastic ones (maybe).
I think while the kids are young you should just go with what the director says. Transition will occur as they experiment and gain experience. Vandoren is good, but they are not the best.