you are right I shouldnt compare him with demon prince, they are not playing the same role. Also 2CP per turn sounds meaty, but also remind that it is 2 cp for general command abilities which are meh, not so suck but kind of disappointing. I don't agree with chaos sorcerer's ability = give you 2 free command points per round.
Also rules wise std allegiance ability already grants you huge numbers of rerolling 1s. But no one will count it as giving std players X command points. CP is CP because it is alternative to choose from plenty of command ability. A solid rerolling 1s buff to a unit is NOT equal to CP.
Other heroes who do similar jobs provides more themed and faction-specialized bonus, so that their armies can do better at certain aspects. Some of them even grants a Area of Effect that effect all units in a certain range, and most of them cost 100~140 points, while Sorcerer lord chooses 1 unit and costs 160 points. chaos sorcerer lord a good utilization tool but not so worthy of 160 points. there is no synergy in him. If a std player want a wizard then just ally from tzeentch or a priest from khorne, nurgle is also great.
Also people focus fire on Sorcerser lord not because they are strong unit, In fact it is opposite. Sorcerer Lord have so poor save property as a 160 points hero and usually in a std army sorcerer lord is the only wizard, and killing him would make opponents magic automatically unbinded. For a KO army it is just "no pain but gain" bargain.
So let us compare him with someone else plays the same role, forgive me I couldn't find any other 160-points buffing heroes because they are all cheaper than sorcerer lord:
1. bloodsecrator
bloodsecrator is even cheaper which is 140. the buff effect is even better, +1 attack to khorne units, compared with rerolling 1s to 1 unit and need to cast the spell first and it has a chance of dispelled, and fights far more better than sorcerer lord. If 3 units in range, including himself, does it means he gives you 4 CPs?
2. lord relictor
this guy can do more jobs with 100 points. and also fights better.
3. lord castellant
add 1 to save rolls. 100 points. fights better.
4. knight-vexillor
reroll charge rolls. 100 points. fights better.
5. spirit torment
140 points. rerolling 1s to hit to every unit in a bubble, and reviving models in a unit. Still if 5 units are in range, does it count as giving 5 CPs? totally outperform chaos sorcerer and no risk of cast failure & unbinding. Also an expert of fighting. and ethereal and flying?
6. butcher
140 points. his warscroll is longest of 140 points heroes. Stronger than any of above including chaos sorcerer.
7. warshrine
the same points. 6++ save to all units in a bubble. praying effects totally outperform sorcerer lord. fight like a behemoth. warshrine is so good that some other chaos army will take it.
So my point is that chaos sorcerer lord seems like giving 2 CP each turn, but actually does not. generally all other heroes have similar jobs also have good impacts as chaos sorcerer lord and even cheaper and stronger. Also std allegiance ability itself overlaps with him.
With GHB 2019 changed only marauder horsemen and chaos chariot point, and a little change in chaos aura range, there are going to be less space for chaos sorcerer lord.