And that is where my issue lays. This is D&D, a wizard that isn't throwing spells around isn't a D&D wizard. Somebody mentioned a dwarven wizard soloing the game using a shield....what? Did Kelek use a shield? Vengure? Mestron the magnificent or Elminster? This game is going to be a hit. And rightfully so. And Larian is going to profit from this. Also rightfully so. But please, try to stay true to what put Dungeons and Dragons on the map.
I mentioned you can use a shield dwarf wizard to solo the game its been done a few times now. Because of dwarves getting proficency to use the best armor 2 handed weapons and access to a head band of intellect as early as level 3 if you are smart about it. So you can build a shield dwarf with stats like 17 14 17 8 8 10 and still be in an ok spot because at level 4 you will be at 18 14 18 18 8 10 for stats. You'll get optimum ac bonus and basically only 1 below average stat. In addition you can basically equip 2 hander for melee combat swap to an off hand to get an extra off hand attack for a bonus action then switch to weapon and shield before ending your turn to keep your armor class bonus up. They can cast divine spells by getting them all the scrolls and cast mage spells so you can magic missle and healing word on the same turn if you need to. There is also an item will let you get +1 extra missle from magic missle you can exploit for even more pew pew.
So basically you get a 17 flat ac 19 with shield equiped 21 with shield spell as a bonus action if you need it. You have access to magic missle, healing word, and misty step so you never has issues with ranged damage or healing or closing distance. you have a +5 to hit in melee + proficency bonus the extra attack doesnt matter because your level capped at 4. You dont need stealth mechanics because you have access to the darkness spell if you need it. Also you can just swap asterion in if you need to pick pocket something. Without using him for the fights. or save scum till you succeed for it. You get +4 hp on every level as well putting your around 30-34 hp range at level 4. You basically get to be a better fighter cleric mage and rogue than other classes. And you dont need a bow because you can just ray of frost targets if you need to for ranged damage. Its more exploitable than it should be if wizards didnt have access to all the divine spells as well it would be less broken but still a little over powered at low levels. Currently because of divine spells being castable its brokenly over powered.
Normally low levels wizards are fairly week till about level 5. The headband of perfect intellect and lack ability to role ability score also impacts this a lot with being over tuned. Having above average ability scores is going to make anything feel strong.