Fandral to me seems like a worse Brann. That makes it fair IMO. Not over powered, broken like some people are stating it to be.
Hence why I submitted it as an "overrated" card though I still think it's a good card that could see play.
The difference between Fandral and Brann is that Brann doesn't necessarily double the power of the card, but Fandral very often does, or maybe it does even BETTER than double. That is because most Battlecry cards don't have most or all of their value on the battlecry, but Choose One cards often have their full power as two different options.
Imagine Brann in Dragon Priest.
Wyrmrest Agent is a 2 mana card, and gets half a mana of value with Brann.
Twilight Guardian is a 4 mana card, and gets half a mana of value with Brann.
Blackwing Corruptor is a 5 mana card, and gets a maximum of 2 mana of value with Brann (there is often overkill)
Blackwing Technician is a 3 mana card, and gets an extra 1 mana of value with Brann.
You kind of get my point here. A lot of battlecry minions only have a small portion of their value off their battlecry. Further, because of the limitations of battlecries and the targeting requirement, some battlecries whiff or do nothing if played twice. Dark Iron Skulker, Void Terror, Ironbeak Owl, Sunfury Protector, Big Game Hunter, etc.
This is why when Brann is usually played, he is usually played with battlecries that do a LOT. Antique Healbot. Abusive Sergeant, Azure Drake, Dr. Boom, Twilight Drake, etc.
A lot of Choose One cards however, especially the spells, scale INCREDIBLY.
Raven Idol. 1 mana spell, replaces itself. You essentially pay one mana to get a flexible option. With Fandral, you
gain card advantage and get two discovers. If Raven Idol let you discover a minion and a spell every time, it would be an extremely good 3 mana spell and might even be fair at 4 mana.
Wrath. 2 mana spell. When paired with Fandral, Wrath becomes Deal 4 damage to a minion and draw a card. That's arguably a better card than SWIPE in a lot of situations. And normally, a 4 damage cantrip would be 5 mana, although that might be slightly overcosted if it could only target a minion. But EXTREMELY good at 4 mana. That's a SUPER Mortal Coil.
Living Roots. 1 mana spell. When paired with Fandral, Deals 2 damage and spawns 2 tokens. That's essentially the lower limit on Implosion. If you spawn 2 Imps on Implosion, that was essentially as good as a 3 mana spell. So this scales ridiculously.
Nourish. 5 mana spell. Holy shit. You ramp for 2 mana AND you draw 3 cards. You just won the game.
And even if you get the effect on a minion, you are very often getting an additional 1-2 mana of value. Which is more than can be said for most battlecries. And of course with Living Roots, Raven Idol, and Wrath, because these effects are so cheap, it's much easier to do these as a combo with Fandral than you would with Brann and a more expensive battlecry minion. You can't Brann into Healbot on Turn 5 or 6.
Oh, and did we mention his statline? He's a 4 mana 3/5. And because very few things in the game deal 5 damage, that means a 4 mana 3/5 is better than a 3 mana 2/4. You might feel pretty bad dropping Brann on curve, but you won't feel that bad about dropping Fandral on curve.
So to summarize.
1.) Choose One spells scale extremely well.
2.) Choose One spells are often much cheaper than the battlecry minions you play with Brann, making it easier to combo.
3.) Choose One effects rarely whiff or overkill.
4.) Fandral is a better body on curve than Brann.
Fandral is not a worse version of Brann.
Fandral
kicks the shit out of Brann.