Tactician class has 4 Slam cards in his deck, which does amount of damage equal to current defense (double on ++) to both, hero and enemy, and I had similar problem with them like you with Bash for Barbarian.
I sometimes ended up with 6 Slam cards in my hand, because I did not use them at all (or got rid of them with enemy attack 1 when having defense 0) or sometimes I had 6 Upgrade cards or non attack cards when meet Golem (high attack and health).
When you go to your deck, you can remove cards for 10 gold by clicking on them, and thats is what I do first when playing Tactician, I remove that Slam cards.
Additionally, I only put ++ new cards to my deck.
It would be better if system would allow only 2 same cards in your hand, but I know it is roguelite, so it must be random heavy and depend on your deck building, but this is not easy since it costs a lot of gold and time to make it right.
I think that best option would be ability to organize your starting deck before first level of dungeon, and later on current rules.
I mean, you have access to all your class starting cards, and can decide what cards you want in what amount, but being limited to total of 25, and each card could appear 1-4 times (and some better ones 1-2 times).
This would allow to tweak your own play style, improve tactical aspect, and reduce luck aspect.