Excellent reply, actually. However, do you think that is the norm?

no it doesnt. ofc there are many counters.

this. i had a 3v3 game and this is what happened:

mass charm > foul grasp > foul grasp > mass charm

it was just frustrating.

Strong choices. 

Well, last night a premade team faced my premade, they chosed double rook, here is the result

I know the discussion is not around this anymore, but it was the OP main topic.

Double tower rook build, yes Sir. Thanks.

Game theory (it's a branch of social sciences) suggests that if one team plays as one type of demigod, then the game should never be started. Here's what should probably happen if teams were trying to maximize advantages:

1. Forces of Light pick to go all Reguluses

2. Forces of Darkness pick all Oak.

3. Forces of Light change their mind and switches to all Sedna's.

4. Forces of Darkness switch to all Erebuses.

etc....

The game never starts.

That's why having your entire team play as 1 type of DG is sort of retarded. You're either signing up for an advantage or disadvantage, because 1v1 games aren't balanced in general. Having different types of Demigods helps even things out.

Where in the world are you getting those DG X < DG Y relationships? Also, why do you assume that every DG only has one build? Furthermore, how do you know that the best counter to XX is YY? Could it not be YZ? 

The fact that different Demigods have different strengths and weaknesses? Even if you choose different builds, there are some things certain Demigods will not be good at. Sedna will *never* be good at AoE, no matter how you build her. Torchbearer isn't a tank, no matter how you build him. Unclean Beast will never be able to heal or shield. Demigods have certain advantages and disadvantages, even with build differentiation. Demigods aren't homogenous.

Take the actual example I gave. I really can't see how anyone other that Oak could counter 4 Reguluses. Four Oaks (it could be pulled off with 3 or even 2, probably) actually do a really good job countering 4 Reguluses. If my opponents switch to all Oaks, there's no way in hell I'm going to stay with 4 Reguluses. It's no longer an optimal combination. I'm going to switch to something else. There is too much homogeneity with four of the same type, even with different builds. This allows a specific counter that will be better, because there are certain things that each specific demigod *cannot* do, even with differentiated builds.

Yes, we know that. How does that help prove your point? Lets say DG build X1 is strong in aspect A and weak in aspect B. DG build X2 is strong in A and weak in C. DG Y1 is strong in B and weak in C. DG build Y2 is strong in D and weak in E. DG build Z1 is strong in C and weak in B. How does that information tell you anything about which DG counters which?

Answer: it doesn't, and in fact does not even support the conclusion that such DG X < DG Y relationships exist in the first place. 

Lets talk about 3v3 since thats the standard format and baseline. Lets say the enemy team has 3 Regs. Number of required Oaks = 0. Number of Required *Any Specific DG* = 0. So lets say your team jumps into my game. I have about five 3-DG combinations that I am especially fond of, none of which involve doubles. Your team picks 3 Regs. My team does not change anything and proceeds to stomp you anyways because 3 Regs is bad. 

Additionally, team automatch features generally do not let you see your opponents pick of race/character/etc before you are actually playing. I assume that this is how it would be done for a DG team automatch, so this behavior would never even be possible, let alone probable.  

I've lost with the trip reg team. It's not as imba as most people think. 1500 damage isn't that much either if you have support. Not to mention, theres VERY few maps where you should have 3 regs in range on the same target, the only one I can think of is Levi, and not if they're anywhere but along the inner wall. My premade used to do this all the time, infact, we got more rage quits than ever even though its much less effective than our current setup.

Never used poisoned dagger with regulus tbh. Back then I ussualy turned off favor items, as they seemed iffy to me.

All it needs is a bit of HP stacking from each team member, which most people do anyway, and a Sedna to heal the wounds, which most premade teams have as well.

Mmm... if you even touch a reggy they tend to die, which is why this trip snipe strategy is nothign more than an annoyance.