I'm not really a fan of obviously tiered magic systems
I don't think it's very interesting, or even makes a whole lot of sense (but I guess it could make sense depending on your explanation of magic...)
like, skyrim's spells, for instance, have very obvious tiers. firebolt is, basically, an upgraded flames. it behaves slightly differently but even that is just a range upgrade
then fireball is an upgrade to firebolt (which is really confusing by the way), and incinerate is an upgrade to fireball. then you have fire storm which seems like an attempt to make a cool-looking really powerful spell but in practice it feels completely worthless to me
anyway the point is I don't like tiered spells
I'm sure they're more straightforward to balance, but what's the fun in taking the easy route anyway