DuMorne was only interested in using Harry as a weapon, Ebenezer in seeing that Harry wasn’t another Warlock. One of the charges levelled against Harry by the White Council was the unconventional nature of his apprenticeship and assumption of Wizard status. Harry admits himself in BG Carlos is much more technically accomplished than him, but Carlos had a longer and presumably more thorough apprenticeship.
Therefore the facts would appear to show Harry is indeed notoriously poorly trained for a Wizard, but a Wizard isn’t his only role, he is a Starborn, and I suspect there is no training for that. He is the Warden of Demonreach and there is no one to teach him that other than Alfred, and he seems to have learnt all about Demonreach and it’s capabilities and he did just solo a Titan so his training there looked complete. He is also a PI, and Nick Angel appears to have done a great job there, and as a father, well Harry is still learning, but his tutor is Michael Carpenter so he is learning from the best.