I just ran a game where the wizard was an Evoker. And when we played in the naturally occurring areas - dungeons, caves, outdoors, even in a castle, it didn't matter. He cast fireball as often as possible, used his Evoker ability to make all his friends immune to the damage, and threw them with impunity. He could place it to avoid destroying the wood and rope bridge, etc. Always worked. Always exactly where he needed it. Shrug.
When he didn't throw fireballs, it was Firebolt. And that was all he took. I mean, he used his ritual to throw up a Leomund's Hut, and other things to ignore worrying about resting, etc., so didn't have to worry about having it memorized. He used his Detect Magic ritual to do that. So, again, unless I continually ran some kind of clock (which gets boring every. single. adventure), or specifically built environments to counter him (which I did have some monsters resistant to fire), all he had to do was throw those around. The rest of the casters in the party filled in the gaps (Cleric, Twilight Cleric/Sorcerer, Rogue/Warlock, and Arcane Archer).
And the Arcane Archer was the weakest of them all (which that class is), and always went unconscious in most fights, without targeting him specifically.