So I have dilemma and was wondering what other people would do in this situation. With Rhyperior being a very solid Mon' in two types of offence it makes him very useful.
With the upcoming potential raid boss switch into Dialga his name is popping up in the Top 10 counter list. This helps because i know Fighting types e.g. The Champ is going to be your supreme counter however i will explain my situation below:
I do not have a full team of Max Machamps, in fact i only have two Machamps with decent IV's and levels.
So my raid group is a size of 6, most of which dont use the supreme counters and play more for fun. We do manage to complete all Tier 5 raids however it will usually take a rejoin so i need a team of 12 most times.
My Team 1 is:
Breloom Lvl 30 100% IV
Machamp Lvl 30
Machamp Lvl 30
Blaziken Lvl 36
Mamoswine Lvl 30
Hariyama Lvl 30
As you can see my team is less than your supreme list, however it will do the job.
In my second team i plan to run a Rhyperior, I have a level 31 100% IV Rhyperior that is a monster with Smack Down / Stone Edge. I only have 3 TTAR SD/SE so I really do need him as a rock team addition.
So my question is, is my best option to buy a second charge move on Rhyperior and run it with SD/SE+EQ or do i power up my level 20 Rhyperior that is 15ATT 89% IV? with Mud Slap / Earthquake. Will Smack Down / Earthquake still be a viable combination? It will cost around the same amount of stardust, and im not someone who is good at holding back on stardust usage so i normally hover around 50,000 Stardust, so which is the better option to go with? So is Smack Down / Earthquake going to perform significantly weaker to Mud Slap / Earthquake or is it still viable? I do have one Groudon however this is level 20 and requires a lot of investment.
SD/EQ Rhyperior is not viable, the difference to MS/EQ is huge. You're better off using a Dragon to deal neutral damage to Dialga than a SD/EQ Rhyperior.
That said, I don't think you need to be overly concerned with the quality of your rejoin team with 6 raiders. You should have plenty of time to revive and heal your first team if the others have similar or better lineups.
I actually think your best option would be to complete Machamp raids to catch better Machamps and, after you get a good one, level that one up. It'd cost you the same stardust as powering up your Rhyperior since it's also level 20. But as you've acknowledge, Machamp is a better counter than Rhyperior for Dialga.
From your suggestions of powering up Rhyperior or getting a new move, I'd choose powering it up. There aren't any scenarios where it's better to use SD/EQ (or MS/SE) over MS/EQ or SD/SE. SD/SE+EQ is best utilised if you have a ton of Quick TMs, but if it's about the same stardust (and candy cost), I rather have two Rhyperior than 1 that requires lots of TMs.
The only pokemon that can currently surpass Machamp against Dialga is Groudon, and only in the sun. And even with said sun, Rhyperior only ranks as the #5 counter, falling behind Hariyama and Breloom. Outside of the sun, it falls to #9.
The issue with Rhyperior is bad moveset (same with every Ground type) and a weakness to one of Dialga's STAB types by virtue of its rock typing. Same goes for Mamoswine unfortunately. Of you really want to gear up for Dialga, then grab a random raid Machamp. Even a 10/10/10 will perform better than Rhyperior in this scenario.
