Think about a class variation and balance aswell.

There are already two dex based trees, which incidently also synergize with one another.
On the other hand, there is only one strength based tree which mostly syngergizes with Int based trees.

As such, building a warrior realy boils down to either playing a hybrid or playing a character that only has one skill tree, investing the spare points into the armor skill and such.
This makes the warrior into an extremley dull experience which realy isnt helped by dual wielding at all (if anything, its one more thing to dump your stats into, ive tried playing a pyromancer/warrior hybrid with dual wielding and while it does work out in the end, i feel like his progression would be quite a bit faster if id have just ditched dual wielding altogether and gone for two handed instead, pretty sure the same is true for more syngergetic trees like geomancer)

Warriors need more options. Summoning master will probably be governed by Intelligence yet again, im actually quite afraid of the summoning master tree making warriors obsolete. Using summons to tank is already very effective in Original Sin EE, having a full tree for that means that you can make a utility mage that also serves as your tank without having to invest any points into strength.

The thing with divinity is that it is great that it has no dump stats.
This however also means that too many skills are, for thematic reasons, governed by the same stats and some stats are, for gameplay reasons, not governing any skills.

in DnD based games, this was never the case. As it was already pointed out in this thread.
The situation of having the main damage class and the main healing class AND the main utility class all beeing governed by the same primary atribute, together with a skill system that allows you to pick up usefull skills from all of those trees with minimal point investment leads to an extremley biased form of character development.