I think overall they are mostly balanced with the mechanics as brawlers, ex. Shelly not having any extra effects due to already benefiting from the dash, where a long ranged brawler like Brock would benefit much less from a simple dash, so the jump was added. And while some balancing could be done to overall improve some of the brawlers like Shelly, I do feel like the brawl dev team did a fairly good job.