Defensive Move Set doesn't matter?
Conclusion first: it does matter but by only a tiny little bit.
Think about this: What really holds a gym?
Only in three cases:
Case 1: No one visits the gym;
Case 2: Someone visits the gym but doesn't beat it;
Case 3: Someone decides to beat the gym but fails to do so.
Case 1 is the most significant factor of holding a gym. Therefore the location of the gym largely determines how long it holds. Not your Pokemon, let alone the move set.
Case 2 could be divided into 2 sub-cases:
Case 2a: That "Someone" is a teammate;
Case 2b: That "Someone" thinks that taking the gym down doesn't worth his time.
Thus, local team distribution and the level of the gym are the other two major factors of holding a gym. The Pokemon inside the gym also matters, say the difference between Chansey and Gyarados (that's why we all want Snorlax/Lapras/Chansey). But not the move set.
Case 3 is the case where the defensive moves could make a difference. However, that difference is getting less and less significant as most active players are above lv30 and are able to solo a level-10 gym. So moves may matter more at the beginning of the game. (Go blame the CPM settings.)
My suggestion is that one should study the Player Psychology (i.e., what deters a rival player away from beating a gym) instead of the defensive moves.
If a rival trainer is taking down your gym, the obvious way to hold your Pokemon longer is that it gets higher placement. Therefore even CP matters more than move set in defense.
Really, if I want to beat a Snorlax, I don't care whether it is Z+BS or L+EQ. The former is more annoying, I'll give you that; everything else is just a matter of potion usage. On the other hand, if I'm hurrying to work/school/dinner, I won't go back to retake the gym even it is a Pidgey gym.
Answers
Very true. Many times I've used lvl 20 throwaway mons to attack gyms when I have no potions. The difference between a lick/earthquake and Zen/slam snorlax is massive.
When taking unlimited consumables out of the equation the gym scene changes quite a bit. It was different back when I leveled up frequently and got plenty of revives and pots.
Does defensive moveset matter...at all?
Yes...but it's certainly not the most important factor. Not by a longshot. It goes:
1) CP/IV
2) Pokemon
3) Moveset
Ppl are focusing more on the least impt choice than anything else.
I've been saying for months on here to the people asking if they should power up their 100% IV Dragonite or whatever with a sub-optimal moveset.
If someone wants the gym, they'll take the gym
Are some defenders more annoying than others? Absolutely. If I see a gym of 10 Dragonite it's going to be way easier to take down than a gym of 10 Snorlax.
But if one gym of 10 Dragonites has all DB quick move, and one has all SW quick move, I'm never going to back out halfway through. Like..."aww shucks I guess I'll go walk another mile to a different Dragonite gym"
This has always been true...
This is why I'm a proponent for high IVs for certain mons (Eevee) since you can just see in some areas, 100CP can make all the difference from being on the top or bottom of a gym...
As you mention, level creep is here now too so most gym players in my area is level 31+. Look around Los Angeles, I'm sure you'll see level 10 gyms with very high CP and stacked with Dragonites/Rhydons/Snorlax only.
Also, you have to factor in at high levels, powering up cost a lot more candies stardust so if you get an extra 100CP from your IVs alone, this could be 5 powerups later meaning for some mons, it could be 63 Lapras candies (or Lax/Dnite), etc...and 46k in dust...(at level 39).
Once I start attacking a gym, I make a point of taking it down completely, so that I do not encourage the use of weak-but-high-CP defenders. I do not know the movesets before my first attack. Thus for me the movesets indeed do not matter at all.
I made it main main goal long ago to find and occupy gyms protected by their location. My current crown jewel sits in the middle of a motorway junction, within the vicinity of a custom station. It can only be approached late at night on holidays, when there is next to no traffic, the station is closed, and the cover of darkness stops any noisy drivers to sic traffic police on you... Luckily the gps cheaters still have not discovered it.
I certainly agree that "player psychology" is by far the most important factor. Including "is it worth" going to that distant gym? (though that is no hindrance for spoofers).
In my, weatherwise, rather challenging area, distant gyms that are not accessible with car tends to stand longer, or by dominated by spoofers.
Being obsessed with high IV and best move sets are probably more for our own vanity than the sake of actual "gym efficiency". :-)
