Yes and no, but it is not that simple. What you're proposing is essentially a new system similar to Awakening to balance old heros. A new system is much harder to implement than just a new hero, we're not talking a 1-2 times harder. We're talking about a linear equation based on the number of heros available.
1) First of all, the Awakening system is not yet finished as ~60% of the heros are still missing their Awakening.
2) The system you're proposing is essentially just another Awakening with no imperative theme. It is basically Awakening part II, because Awakening part 1 failed to do its job. What you're saying is that the current Awakening is a failure and the game needs another Awakening system. Developers will take criticism and feedback from players, but they will not admit their creation as a failure. It is just part of a development cycle for software developers, the developer will always stick with their original goal as they have already invested time/money/effort in it. The only reason why they would actually start over and scrape the current Awakening system would be that their sales and revenue goes down drastically BECAUSE of the current Awakening implementation.
3) Let's think from Lilith's perspective, would it be easier to just release a single hero. Or easier to implement a new system, then balance every single hero in the game (~70 heros in total I think), test all of them, reduce bugs down to a minimum, then finally release it. Chances are, it'll probably take Lilith a week to release a broken hero and make tons of money whereas implementing a new system would take them months. The revenue and profit that Lilith can gain as a direct result of such a system is unknown. If you can do predictive analysis, then be my guest and show me the statistic. Life cycle of mobile game typically don't last long, so it is always ideal for developer to make the most amount of money in the shortest amount of time when possible.
TL:DR, Why make a new system to balance the game for everyone, when you can take the easy route. Releasing OP heros and make tons of $$$ from top spenders is arguably more beneficial than to cater towards bunch of f2p players.
Thanks for the thought put into your post. You make several great points, and your thoughts are along the lines of what Lilith is doing. I did not mean to imply that creating a new system was simple; however, either re-keying existing systems (something that tends to peev whales that invested according to the existing systems' rules) or making a new system is what might be needed to move toward a more sustainable game and revenue model for Soul Hunters. Actually, I think an expanded or multi-part Awakening would work, so a brand new system probably isn't truly necessary; however, new systems tend to drive revenue so I thought that it might be more attractive to frame it that way.
Adding new heroes without rebalancing aspects of the game is something that certainly is easier, and is extremely attractive; however, there are downsides to outmoding your "old" parts of the game without rebalancing. This video goes over some of them in an entertaining way:
https://www.youtube.com/watch?v=tL_bCwiUKNE though you probably already have a good grasp of the effects based on the thought you put into the post.
The cost of constant accretion in the pursuit of revenue is, eventually, cluttering the game to the point where usability suffers greatly. When usability suffers in a mobile game, it is really, really, really, really, really, really hard to motivate new players to stick with it because there are so many other options out there that they can dive right into. The result is that there is a risk of a shrinking player base.
The eventual result crushes everyone involved:
1.
New players find the game unapproachable. Just imagine SH having 2x the heroes it has now, and how the various shops would be either jammed full of soulstones or you'd hardly ever see them for the heroes you want. What heroes should you choose? Free players would be totally overwhelmed with no chance to invest in more than fraction of the game content.
2.
Whales lose a key aspect their content, and thus their motivation. What do I mean? In a game like this, other players are content. The mere fact that they are there provide motivation for whale spending. A shrinking player base means a shrinking competitive player base, which means the whales have no one else to lead or talk to, and only have each other to compete with. Stagnation continues. Whales bore, and begin to leave for greener pastures.
3.
The shrinking revenue from leaving whales changes geometrically, because content (other players) is leaving the game faster than content (Lilith putting stuff in) is entering the game, which causes yet more players to leave.
4.
The game fails to produce enough revenue to continue supporting, and Lilith, whales, new players, basically everyone who likes Soul Hunters is out of luck.
I don't have the time to write a book about this, so yes, this is simplified a bit. But hopefully it shows clues that the mere addition of new heroes may not a sustainable model.
I don't have access to Soul Hunter's numbers, but unless their model is already showing signs of failing and they are just trying to spike revenue as much as possible before declaring that the game is no longer going to be sustained (Chain Chronicle global by Gumi did something sort of like this), it doesn't make sense to blast apart the balance and power curve by outmoding parts of the game with new heroes above that curve. Heroes and their role in the core mechanic deliver the main (or at least one of the top) value in the game.
It doesn't look like Soul Hunters is at that point, but just imagine what will happen if they
don't avoid unsustainable accretion. Making a new community like Soul Hunters has would probably take much more effort than trying to improve the sustainability of this already-entertaining game. And everyone who has invested in the game will be really sour, maybe even sour toward Lilith. I liked Chain Chronicle global, and Gumi's shutdown of it soured me toward Gumi games; I wouldn't invest in another one of their games because if they can't manage it correctly like with Chain Chronicle (one of the best, deepest mobile games I have ever played due to the variety of things they could do with the core mechanic, and its closure is the reason I eventually sought out Soul Hunters), my money goes down the drain.