Knowledge or strength?

Of course, the amount of knowledge points depends on the length of the game. And it's pointless to argue if no one specifies the map size. Well, for me personally, an average of 10-15 knowledge points is enough. I believe the amount of strength and knowledge is a balance of dependence on each other. What's the point of having a lot of knowledge if you have little strength, or what's the point of having a lot of strength if your hero is "as dumb as a log" (has little knowledge), right? I find that 10-15 knowledge points are enough, so I can put subsequent points only into strength. And at the beginning, I put almost only knowledge points, up to 5-7, and then I actively invest in strength.
There's also a trick in that some spells don't benefit from high strength, for example, Haste or Slow, while others directly depend on strength - Explosion, Ice Bolt, etc. This should also be taken into account when choosing. It's also worth considering what you will use in the decisive battle - offensive spells or support spells (in this case, by offensive spells I mean spells that deal damage to the enemy - Explosion, Lightning, etc., and by support spells - Slow or Haste, etc.).
In general, the argument again depends on the circumstances. In principle, as with most arguments on the forum.

Added 1 minute ago
In a way, I level up strength and knowledge equally.