The problem with the objective model I’m using for abilities is that removal cards are pretty cheap. Exquisite Firecraft does 6 damage for 6 mana. Final Reward is 7. If I up the value of Ajani and Ob Nix because I think removal is more valuable than say mana gain or creatures, where do I stop? (Btw, I do think removal is more valuable). If I pretend EF doesn’t exist and have to use 2 Lighting Javelins, Ajani gains 8 points- top of tier 3. If I give a similar bonus to Ob Nix, he jumps to the top of tier 2. Seems a bit much. Not sure I agree with extra reductions for negative mana. Right now the mana score is based on a sum of the total bonuses/penalties. So I’m already subtracting the minuses. I’m not sure we need an anti-Koth rule.
Ajani 1's abilities can actually make up for a lack of control cards for newer players, so he can be useful that way. Nahiri is probably the right recommendation, I just don't think he's one you need to warn against. Also, if you have 2-3 good kill spells, Liliana 3 is amazing at low levels, especially for Training Grounds. My level 1 Lili 3 brought my time for four victories down under half an hour on average all the way into Silver tier.