Are there 3* heroes who are worth leveling twice? For events or alliance wars…
Depends on the hero’s you have available.
For wars it can be good to have some back up hero’s since you are able to attack 6 times and can use hero’s only once.
But in early stage it can be benifficial to use them to level your hero’s. So all depends a bit on what you already have and what you are aiming for.
Red - Nashgar/Azar
Blue - Valen
Green - nope (better have Belih-Brienne-Berden)
Purple - Balthazar
Yellow - Bane/Gan ju
All of them are fast and good attack/useful secondary skill.
I personally like to have three for every color (attackers and healers) plus the 2 spirit link (Gunnar and Kailani).
I have every 3* hero and I consider which 3* cards are worth keeping twice.
For AW they are worthy only until you don’t have enough 4*heroes, for events there’s no such need:
mixed heroes work better to cover each other weakness.
I don’t have enough 4* heroes and I saw at the event that highscorers use sometimes two of the same cards e.g. Balthazar. They surely have enough alternatives.
Double Balthazar could be useful to defeat Guinevere, Balthazar and Tyrum can be better, removing his special effect. Or use double Balthazar, Belith (with maybe another green: Brienne) and leaving home other colors.
Earlier in the game it can be worthwhile for AW. Later in the game when you have TC20s kicking out 4*, you will get to the point where 3* won’t be used for AW at all. Or anything else other than perhaps the beginner levels of the special events. I keep 1 copy of each because I’m a hoarder but I don’t ever use them for anything.
I wouldn’t recommend duplicating 3*s expressly for AW, but I do have duplicates of Bane and Balthazar since I take the beginner challenge event quite seriously. I also am holding 2 copies of Squire Wabbit which I plan to use.
As a general rule, I’m in the same boat as wharf lord. I think that multiples of one hero is, frankly speaking, a bit boring. That’s why I try to keep at least one of each, even at 3* level, and then when you have several heroes in each color, they compliment each other (Gunnar and Ulmer, for example). That said, I worked hard for the 2 Squire Rabbits I got, they probably have the strongest attack of any 3*, and I’m ■■■■ sure gonna keep both of them!
Someone said once that if you get stuck skilling up a 3*, sometimes it’s easier to just replace him. If this is true, I need to get a new Gunnar and—after testing—toss the old!