If you had to choose another Machamp
Two choices, no TMs available, both level 20:
1. 15A/15D/12S 93% C/CC
2. 14A/12D/14S 89% C/DP
Answers
That one is easy. The marginal difference between CC and DP should be made up by the better IVs of the first one and with 93% you have a Machamp that is good already PLUS you have the potential to make it great as soon as you have a few TMs to spare.
If you're really interested in the difference in performance, add them to you pokebox on https://www.pokebattler.com and check their performance in Porygon/Tyrannitar Raids
The difference between DP and CC is far from marginal. Against a Tyranitar raid boss DP is more than 10% increase in DPS over CC, while the IV is unlikely to amount to any difference at all. Unless you are reaching a big breakpoint, a small IV difference will never overcome the difference between optimal and non-optimal movesets.
As you said, pokebattler is a good way to evaluate them.
By the time he has won enough TMs to get that first machamp a DP, he'll have accumulated enough dust to power up both.
I don't know what the numbers say. If the C/DP performs better in pokebattler, etc, then power that one up now, use it in t-tar raids, and try to get the TMs to change the CC of the first.
If you need a Machamp immediately, take #2 to L30 for now. The moveset makes much bigger difference in performance than IVs in this case. #1 is better to take above L30 and invest in the long run, but you should only do so after you've been able to fix the moveset.
That said, I would keep it as CC until gen 3 rolls out and we see how they change the movesets this time around. CC might get a buff.
Thank you all for the feedback. I only have one Machamp at level 30 (96%) and all others are at level 20. Machops are nonexistent in my biome so it's all from raids. I can solo Machamp consistently, but I can't raid frequently. I would say that at best I am able to run across 1 Machamp raid a week. The 89% is the best one I've gotten from a raid (except my 96%) and the 93% I hatched from an egg. I want to keep CC and DP in case of a move rebalance (but I have an assortment of 82-87 machamps with CC).
What it comes down to, is I just want another Machamp. I know it's not the wisest investment, but it's what I want to do. I think I'll go with the CC 93% and hope for some better TM luck, but I haven't seen a charged tm in at least a couple weeks.