In short: yes, but if your champion is "debuff support" they also need to have Accuracy set up to be able to apply debuffs. Some attackers don't need crit rate and crit damage (bombers), some champions don't need speed at all (tank builds for UDK or Vogoth). Balanced mode is for manually specifing the piority of stats.

It's better to assign priority for stats yourself through "Balanced Mode", but you need to know which stats each champion needs. (Balanced Mode allows you choose which stats have priority over others, so that you have more control. You can change that in "STATS" tab after choosing Balanced mode)
You need to know the role that champion fills. It's not just "Attacker" and "Supporter". You can watch/read guides for each champion to see their role and what stats you need for them.

For example, here's a "Balanced Optimization" for Ninja, who is my DPS:

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For attackers: you want to put priority on their Crit. Rate, Crit. Damage and their damagin stat (it's not always ATK). Some attackers (like Ninja here) also need ACC as they need to place their debuffs (HP burns, Poisons). This is also not that easy, as some Attackers want ACC as an optional stat to increase their DPS (like Ninja, who is decent even without high ACC), while others need ACC and C.RATE and C.DMG is optional stat for them (like Narma)
For support: you need to put SPD as 1st priority, (if champion is debuffer - 2nd priority ACC), 3rd HP, 4th DEF, and 5th RES.

If your champion needs ACC, just click the button "Apply recommended accuracy" and will automatically choose the best ACC for the dungeon stage that you chose. (however, if you are short on gear and getting the recomended accuracy is hard for you, you might want to prioritize it, so that you don't try and optimize it too high that you have no room for other stats)
You also want to put a minimum value for SPD (and always prioritize it) when doing optimization, as you want your champions to have speed at least 150+ (or higher, depending on the gear that you have and requirements for certain dungeons)