Machamp with 14 Attack worth powering up??

How often are you going to need a 6th Machamp? That's the real question.

So you want to start trying duos! That's why you need the sixth machamp. You will need him and it will help if they are all level 40.

If it was me, I would wait. If you have 5 good powered up machamps, I assume you are able to solo machamp raids. You'll eventually get that 15 attack that you want. It won't be much difference at level 40, but there is a small difference. And when a raid comes down to just a second or so, you'll know you did all you could, rather than wondering if you would have won.

The only reason to power up the 14 is that you can't wait. That's fine too. That's a great pokemon! It is up to you!

In most cases, the only difference between a Mon with 15 attack and one without 15 attack is the level at which they hit their final breakpoint against whatever it is you're fighting. So a 14 attack Machamp might need an additional powerup to hit that last breakpoint, but typically, that's it.

If you're thinking of powering up a sixth Machamp, you might want to check out the breakpoint calculator to see if there might be any noticeable differences against targets like Blissey and company.

I think the biggest difference is that in order to hit the final Tyranitar breakpoint, you'll have to power it up to 36.5 instead of 36. But you'll be able to hit every possible bulkpoint which can mean enough survivability to get off at extra attack in some (theoretical) cases.

This Machamp is amazing, but like other people have said you need to figure out why is it that you need a sixth one.

For Tyranitar duos, 6 are not required (3 are actually enough). Breloom and Haryiama serve their purpose well and Hariyama might be handy in harder sets for more resistance. If you're going for Aggron, then absolutely you need 6 L40 Machamps but chances are.. You're not.

But a L40 14A Machamp will be just as good as a 15A in all known relevant cases, as far as I'm aware.

Did the simulation in Pokebattler:
100% lvl 40 machamp takes 309.2 seconds to clear Ttar with 12 of them dying.
A 98% lvl 40 machamp with 14 attack takes 311.0 seconds to clear Ttar with 12 of them dying.
Over 12 Machamps the difference is only 1.8 seconds.