Multi-Stage, Mixed-Troop Comp Attacks
First off, I have always loved "mass attacks" and am a firm believer that "mass attacks" at the highest levels when you aren't OP *always* require a lot of skill to pull off a 3-star once you simply let enemy base designs evolve and adapt. I have not been a big proponent of "mixed troop multi-stage attacks" by any means (mass witch, when it ruled, was one of the most entertaining/exciting/awesome things this game has ever seen IMO!!), but for a minute, let's assume SC wants the game to evolve to mixed-troop multi-stage attacks, and think about what really might be required to do it the "right" way:
(1) Make it possible for such attacks to 3-star a fully maxed TH11 or fully maxed THX if you have max THX troops/heroes and skill. How else are you going to encourage players to adopt this attack strategy unless there is some benefit to using it compared to using traditional army compositions and/or "mass" compositions they are more comfortable with? ...not to mention that it should be possible for the best fair play attackers in the game with max TH11 troops to 3-star a sub-optimal enemy base design once in a while in war!!!
(2) Put more time back on the clock. No one is 3-starring upgraded TH11 now even if you have 10 minutes of time, let alone 3 min 30 seconds! Multi-stage, on average, requires more time to walk an AQ, surgically clear specific areas/defenses, and so on.
(3) "Buff" mixed compositions. I'm not sure what the exact numbers would be, but suppose your army comp was over 65% ground OR over 65% air; i.e., predominantly just one "mode" of troop. Then you get no "bonus" and your troops' hp, speed, dps all remain unchanged. If you have a composition mixed with air and ground where the % of air and ground troops both fall in the 35% - 65% range (healers count as "ground"?), then all troops get a slight "buff" to their hp, speed, or dps, or maybe "the heroes become inspired!" and heroes are buffed slightly when used with mixed comps, lol. Whatever the case, you get the high-level idea! It could be just a 2% hp increase--would have to beta test with different numbers in there.
(4) "Nerf" troops if they are "spammed". Not that you need to do this, because "spamming" has never worked well unless you are OP, but if > 80% of the troops and heroes are all deployed within a certain tile radius of one another, give the entire army and heroes a speed/dps "nerf" because they are having trouble seeing and coordinating, are all in each other's way, and can't attack efficiently--chaos and confusion on the battlefield ensues, even as they spread out due to their deployment. :)
As much as I enjoy "mass attacks" and fight the notion that they do not require skill, especially once the defenses all adjust, I could see a game where mixed-troop multi-stage is genuinely fun or even superior. I just don't think we are headed down the right path by simply making the Eagle Artillery take longer to activate, or the baby drag rage when only in the presence of ground troops, or by noticing that multi-stage can't 3-star but is good at 2-starring, so making the game a 2-star game (boring!!!). When people say they want "mixed-troop/multi-stage" they mean an exciting version of mixed-troop/multi-stage that can yield a 3-star, and not a boring "safe 2-star" game.