Which attacker should get Charge TMs first? (amended)
L30 MS/SE Rhydon 13A/14D/14S seeking EQ
L30 WG/AT Vaporeon 15A/14D/14S seeking HP
L30 Conf/Pbeam Espoeon 8A/15D/14S seeking FS
L30 WG/AP Omastar 13A/13D/13S seeking RB
L23 Conf/SBall Alakazam 15A/15D/14S seeking FS
L26 RS/HP Poliwrath 15A/13D/14S seeking DP
Considerations:
1. I am from Singapore, so will spend November on Entei raids (main source of TMs). I quit a week after the gym reform and came back a few days ago.
2. Next fast TM will go to my L27 MS/SE Golem (15A/14D/15S) to get RT/SE.
3. Could instead power up a L24 WG/HP Vaporeon (10A/15D/13S) and also have a L23 MS/SE Rhydon (15A/12D/12S).
4. Currently walking Larvitar for 35 more candy so unlikely to evolve another Espeon. Only other Psychic-type attacker is L30 Conf/Pchic Exeggutor (13A/14D/13S).
5. Not enough Abra candy to power up to L30. In my biome, Abra, Omanyte and Rhyhorn are rare, while Eevee and Poliwag are common (but still need to grind to get wonders).
6. My other relevant attackers are DT/OR Dragonite, Bite/HP Gyarados and Count/DP Machamp (all L30 wonders). Not sure how relevant Conf/Solar Exeggutor is in the current meta (mine is L26). RIP to all my prestigers...
Answers
Out of all of those, I would have to say Omastar is easily the one most deserving of a CTM since it gets a significant increase in DPS either way. You want to hit HP though, it's better against Entei than RB. But I'm still not sure you'd want to use a CTM here, there are going to be better options going forward.
None of your other options are good, they all have horrible risk/reward ratios. Rhydon already has the best moveset against Entei anyway and should not even be considered, while Espeon does get a certain improvement but changing PB->P is not worth a CTM.
Powering up your other Vaporeon and Rhydon is a fine idea if you need more mons for your Entei team. But seeing how you have the Dragonite and Gyarados at high level already, use those instead.
I just finished a whole month of Entei. My team with 6 maxed vaporeans. That's the way to go. You can sub one of those for a big ttar, but the vaporeans are the way, the life the trust. though 50/50 sucks on TMs. I bet you'll get more if you're raiding a lot though.
Omastar kind of sucks :/ I wouldn't do that personally. Perhaps the Golem as number 2 pick.
Rhydon, Vap, or Espeion are IMO the best candidates. Omastar has an advantage in that for many of it's targets, either of it;s other charge moves are better than AP. But, it's poor base stats make it only okay even in it's best matchups - unless you have a legacy one with RT.
I would not walk a larvitar - do TTar raids to get more TTars, and just use the candy to power them up; TTar raids are the one level 4 raid people are still willing to do