Different Movesets of Same Species

I have two level 30 Dragonites: one with DT/OR (generalist) and one with DT/Hu (for soloing Machamp). I also have three level 30 Exeggutors, with Conf/Psyc, Conf/Solar and BS/Solar.

My two level Alakazams with PC/FS and Conf/FS do not count because I use them for the same purpose (soloing Machamp and Gengar). Would consider powering up a third Alakazam with Conf/FocB to attack Normal-type gym tanks.

Unfortunately, I do not have a second Tyranitar, which remains a distant goal. Powering up two of the same legendary is contrary to my playing style and would cost too many Rare Candy.

Psychic is so damn lame and same as Zen Headbutt, if it gets Confusion + Future Sight then it is good.

I have a few offensive and defensive duplicates. The two that stand out in my mind:

Exeggutor C/So and C/Se
Venusaur V/So and R/Sl

I have some with different offensive movesets. The obvious example:

Tyranitar B/C and B/S

And of course the "good enough, don't want to waste anymore TMs" movesets, like:

Golem R/St and R/Rb
Vaporeon H and A

Groudon is the first legend that I have powered up more than one of. Both from level 25, one to 30 and one to 35. They both currently have M/So for fighting Kyogre, but when Kyogre leaves I plan to change one to Earthquake.

Yes, I do that for all mons. For legendaries, this is my only exception to my self imposed "only 1 powered-up legendary per species" rule.

I do that for most weather boosted mons that I evolve and cannot bother to TM in case they become legacy or a shift on Niantic's part makes their moves better. The only exceptions I make for this are legendaries (because I can usually only gather enough dust to power up one once it goes away as a raid boss), and certain "necessary" meta-relevant movesets like Machamp's.

I have two perfect Scizors that both got double bug movesets and I've been wanting to change the second one's to steel, but the one I maxed has barely seen any action and fairies aren't a problem in my area so I haven't bothered.

I do collect legacy moves on everything else, just for lulz

No. I only power up one of each mon but I would let them learn different type moveset if the mon is not pure type.

I have 8 Dragonite, 3 DT/OR, 3 DT/HU one each legacy DB/DP and DB/OR. So for me Rayquaza will be strictly a Flying-Attacker and I will only power up one Salamence with double-dragon moves. Flygon has no place for me. I powered up two Groudon and will change SoB to EQ on one when the time for a ground attacker arises. Metagross will be steel only for me. I don't have a Mewto but Psychic is covered by Espeon and Alakazam or Lugia even though I have my Lugia with Flying moves. Exeggutor is strictly grass! Psychic is just too weak!

I maxed out 4 Dragonites, two with outrage, one with dragon claw and one with hurricane. Initially the hurricane one was for machamp raids but now the maxed out outrage and dragon claw ones are strong enough to use for machamp anyway... Might tm it back to outrage

Also have multiples of gyarados with the dragon, water and dark movesets

I power up as many of any species I like. I don't and won't restrict myself to one of each species as that would hold back the potential that my teams could have (ex. Raikou >>> Jolteon, why would I not power up more Raikou if I have the resources).

Only if they have different forms. For example, normal Banette SC/SB & shiny Banette H/DG (though currently has shadow claw so not the best defensive I guess). Or if they differ by gender, in which case with shinies i'd have 4 of the same species and try to get all possible movesets on them as long as it advantages them somehow.

I do not train duplicate Pokemon, so if I power up more than one, they have different sets. The only exception to that rule is Machamp, which I have more than one of with C/DP. But that was before Hariyama and Blaziken. If they had been around when I was forming my Fighting team, I wouldn't have any exceptions.