you did what I couldn't do!

Hey. If so, I cheated - half of my creatures weren't Guild ones, just neutral :)

I'm actually surprised by Mugging and Sleep Dart. I personally like Umber Arrow and Hunting Trap better

I think we play different styles. My choices come from the fact I have that crowd of strength-stealers - 4 creatures or 8 if you count with echoes. Mugging is amazing to beat Aggro Light since it works well against protection on slender creatures - and even without protection, Mugging is a spell with immediate damage 3 (if not armor) which is good against Aggro Nature too - extra removal. But together with strength-stealers, Mugging becomes something bigger.

Sleep Dart vs Hunting Trap - Usually, creatures with decreased strength can't be killed by Hunting Trap - Sleep Dart is better in this case. Also, Sleep Dart needs only 1 turn to remove Wild Hog, Badgers (even buffed), it ruins Marsh Walker (unlike Stoneskin Poison).

Generally, I designed my deck to fight against low-mana creatures of Aggro decks, with a mission "kill them all before they are buffed". I think Hunting Trap is more helpful against big creatures. For example, I needed it this WR when I encountered beefy powers like Helian Elite, City Planner, etc. But I have extra buffer, 2 Dark Knives and 2 Ludian Thespians with their 2 echos - it sometimes helps to remove a big beast.

Umber Arrow vs Bound by Her Will --- since I have many strength-stealers, I prefer Bound which allows taking a creature under your full control - one of the best targets is Guild Enforcer. I like stealing Oni Spellsword. Also, Bound allows stealing many creatures without the help of strength-stealers, like Walker, Beetle, Choralis, Street Conjurer, Cursed Obelisks, many Light creatures. Umber Arrow needs 2+ creatures on the opponent's board - this is another limitation. And you often can't remove creatures by colliding them - most low-mana Nature creatures, protection is trouble too for Umber Arrow. But in many situations, Umber Arrow is the best option - ideal against Anubians, for example, as you said, sometimes one lucky Umber Arrow can win the game. I thought about having 2 Bounds and 1 Umber Arrow but... I thought it would be too many spells of that type.

So the conclusion of mine is: my deck is Strength-Stealing Deception and it has its own ways.