OP's book has 2x Poisoned Blood
Show me any non-dark-school that can do that. With ANY card.
1x Jinx
Show me another non-arcane card that can do what jinx does.
1x Galvanize
Show me another non-holy card that can remove corrodes.
1x Magebane
Show me another non-dark card with this effect.
1x Chant of Rage
... same text
I don't think 'no other card can do what Poisoned Blood' can do is the point. It would be bad game design if another card did.
Rather, I assume the complaint is that because some cards are the 'simple' and 'obvious' answers to some problems, they get chosen because they can be afforded, at the cost of variety and 'thinking outside the box'. Thus countering individual spells become more of a concern in book construction than countering various mages.
By this I mean that if everyone packs a couple of Poisoned Bloods, then players will inevitably start thinking along the lines of "how can I work around/remove my opponent's inevitable Poisoned Blood play?', rather than 'Hmm, he has brought a Wizard. How might this Wizard plan to prevent me healing or regenerating, and how can I fight that?'
So: Poisoned Blood is used to prevent healing and regeneration. A Wizard who could not afford a PB might use nullifies, reverse magics and such to stop the Healing spells, or use dispel to get rid of regen enchantments and so on. A Warlord with no PBs might instead simply plan on dealing more damage, to nullify the regen through sheer output ("I don't care if you regenerate 2 damage when I can deal 4 more!").
I like theme in my games, MW included. So anything that can enhance the theme of different mages approaching the same problem with different tools gets a tick from me. I have suggested limiting the proportion of the spellbook dedicated to out-of-school cards. Others have suggested just making the books bigger or smaller. The best solution is probably just playing more with different players. Encounter new tricks. They are out there.