Power up these Poliwraths ? And TM the 2nd one?

Poliwrath is a filler mon. I personally will TM a Poliwrath to double fighting at some point. That is because I have 9 or twelve of them in my bag and only one has a double water moveset.
If you have gone through a lot of candy without getting what you want, do it. Just pick one with at least 91%. If you don't care about legacy moves, well there's your candidate. 2 TM however (and probably more than that) might be a waste.

Most will recommend NO power up on either Polywrath since machamp is essentially a stronger fighting Polywrath.

Also, anything below 89% is considered pretty low for power up nowadays, given that it is easier now than before to get high IV mon thru raids.

That said, I have 2 fighting Polywrath maxed, from the time before machamp raids and TMs, and also because I like the odd looking, ball of pure fighting water dude.

Anyway, if must spend stardust and TM, then do so for the 93% only, and leave the 84% alone.

Don't power up both. 10 ATK IV? Well, not worth powering up, and is also useful at the current level. The CP 1731 one? Not really worth spending so many TMs on a Poliwrath, keep it as a trophy.

Poliwrath is one of many mons, where I feel the best course of action is to find a L30 Poliwag and evolve that more or less regardless of IV's. Stardust is too important to preserve and Pokemon level is more important than IV's.

For instance, I haven't spent a single stardust on Golem. I just evolved three low IV L30 Geodudes I foudn during the rock event and during a visit to a Geodude nest. Sure I would rather have a super high IV Golem, but these three boys get the job done and I can use my precious stardust elsewhere - like on legendaries where you can never find one above L20.

But useless legacy moves may suddenly become great.
A (not really) example was Discharge for Magneton.

I would TM Mud Shot and see what you get. Both current moves are better than mud shot. I would leave Submission alone and not take the 1/3 chance of getting Ice Punch.
Not sure why all the hate towards Poliwrath. If you are not swimming in Machamps, he's a good stand-in.

No... I have a 100IV Poli and it has not much use hitting anything.