The reason to specialize isn't because we're incapable of hitting "sufficient dice" otherwise, it is to get there faster due to having more focused cultivation, and it is to streamline combat-time action economy[1].
If we had enough time we could totally develop multiple styles to Monster-competitive levels and situationally switch loadouts in-between. Hell, that's what Liling did as prep to ambushing us; tracking, speed and spiritual defense instead of a simpler "more death".
No one else that I can remember has made that argument and most everyone has argued that if we don't specialize we won't be able to deal with a hypothetical threat because we won't have the dice to beat their defense.
However, in the interest of argumentation and debate, there is a counter-argument to be made. Getting more archery arts does not streamline combat-time action economy any more than having archery/music. We will have more choices to make at each stage of the fight with a pure archery build, as each tech that could be used at certain stages of the combat would have a competing tech that could just as well be used. In that instance, the choices have decreased value as there is another option that could just as easily be used.
With music/archery build, we have a limited number of choices for ranged combat, and then a limited number of choices once they get into effective range. In other words, the choices are more valuable in a music/archery build than in an archery build. Or, in other words, the time we spent on each art has more meaning and value because the techs from each art would be used more.
As for the speed aspect, I can see an argument that could be made there. Reaching the benchmark faster means having time to cultivate other arts that don't impact battle. That's an argument for specialization but not against using both music and archery. We get 2 archery arts and 1 utility art in an archer specced build, and 1 archer art and 2 music arts in the hypothetical music/archery build. The question then is how much value is that utility art and how much does it help us. We know the answer to that question for the music/archer build, not necessarily for the pure archery build.
Yes. By specializing, we increase how often our attacks hit, and hedge against something unexpected changing the die totals. Alternatively, by getting bonuses from non-talisman sources, we free up our talismans to be used for defensive bonuses or more qi reduction or whatnot.
True, but that is not the crux of the argument that many people are making for why we need specialization. People's arguments that we need specialization in order to get the amount of dice needed to defeat the mythical opponent is paradoxically opposed to the argument that specialization allows us more leeway in dice to get better defense. You can make one argument, but I don't see how you can make both.
As for increasing how often our attacks hit? That is again the argument that specialization is needed to get the dice to effectively combat people. However, our build works around this by being debuffed focused where one hit further increases our chances for other offenses to hit. However, this argument is opposed to your argument that by specializing we can then focus our dice on something else that is needed.
The world is also bigger than Sun Liling. Unless we hit aomething like a level cap for, say, music, the specialist will nearly always be stronger than the generalist at the same level.
Splitting our build means we will be weaker at 20 years old than we would be if we were specialised. Correspondingly we will be lower on the metaphorical ladder.
And yes. Build are more complex than this. Certain investments can produce qualitative shifts in the game that have disproportionate quantitative effect. For example: if we get stealth high enough to effectively go invisible in combat then anyone who lacks sufficient perception or AoE will be at a huge disadvantage, as we will have effectively negated all their offense dice. Guarding against being trumped like this is hugely important.
However, I see absolutely no reason to think that going both music and archery would produce this kind of qualitative advantage.
And I don't suppose that if I gave some reasons where it could be a qualitative advantage the hypothetical archer won't come out again? The hypothetical archer that will always be better than us unless we go a specific route?
If we are fighting someone, then hopefully we already know what they are good at and not just picking a random person from the ground. Because we are a sneak, we don't like engaging in a fight, and we have a great tool for gathering information on enemy cultivators we can know if this person prefers to fight at range or up close. Having both options allow us to pick the method of fighting that gives us the advantage.
Having a dedicated single target ranged options enables us to bleed people from afar. If we know that they prefer close ranged, then that gives us the incentive for fighting from afar. Unless they have ranged capabilities equal to ours or superior, or have a large distance movement art, that places them at a huge disadvantage. And we know that they don't have ranged options that are superior to ours because we did our homework.
Having a dedicated AoE close ranged options enables us to bleed people up close, trap them where they can't escape, and debuff all of their stats. Unless they are our equal or superior in close ranged combat, then they will have a huge disadvantage because they can't gain distance from us to utilize their specialty. And since we know that they don't have superior close ranged options, because we did our homework, then we will have the upper hand.
If they are equal to us in both areas, then the fight would be even and competitive and not a one-sided slaughter that people are claiming it would be.
We won't be choosing to fight an opponent who is superior than us in both options unless we are bringing friends, and if we get jumped by an opponent who is superior to us in both options than we engage in stealth and run away (Sun Liling). The same thing happens if we get engaged by an opponent in the range that they are superior to us.
If we can't stealth and run away, which I might add is what we are really good at and will probably continue to be really good at, and the opponent is superior to us then something drastically wrong has happened outside of combat and being a specialist in one area will not save us from this fight.