Any chance of a nerf to Thief Silver?

Lately, I've been going through Silver challenges a lot. I have ten of them done so far, have "skipped" two, and haven't touched the other three. Thief is one I've skipped, come back to, and skipped again. (Priest I skipped, but haven't been back to yet, and Transmuter, Crusader, and Tinker are the ones I haven't touched)
Thief Silver is...silly, for lack of a better word. I managed to finish all ten of the others in no more than four attempts, and most in no more than two. But I've put at least seven real attempts into Thief and have never been anywhere near boss-ready. It takes WAY too many resources, primarily blankspace, to level up, unless you get lucky.
I mean, I know what to do. That isn't the problem. The problem is that I'm not finding what I need to find fast enough, and it's wasting too much blankspace.
Just to be sure, here's what I do:
Level 1: Kill the nearby chest to get LEMMISI.
Use LEMMISI until a level 2 or a monster very close to a level 2 is revealed.
Find two attack boosters, OR find one booster and convert LEMMISI.
Find three health boosters OR a health potion.
WEYTWUT to get to a level 2.
Reveal all blankspace around the level 2. (Usually, this involves WEYTWUTing it)
Kill it: Hit, potion, (2nd potion if maxHP < 13), hit, WEYTWUT, hit.
Level 2: Effortlessly kill the other two level 2s.
Kill a level 3: Hit, regen, hit, WEYTWUT, hit.
Level 3-4: Same dance as before. Kill any chests that are able to be killed.
Level 5: If it's revealed, kill the level 9 chest for a fireball glyph.
Level 6: Run out of blankspace and give up.
Is there something I'm doing wrong, or is this challenge really just an RNG thing?
Thief Silver is...silly, for lack of a better word. I managed to finish all ten of the others in no more than four attempts, and most in no more than two. But I've put at least seven real attempts into Thief and have never been anywhere near boss-ready. It takes WAY too many resources, primarily blankspace, to level up, unless you get lucky.
I mean, I know what to do. That isn't the problem. The problem is that I'm not finding what I need to find fast enough, and it's wasting too much blankspace.
Just to be sure, here's what I do:
Level 1: Kill the nearby chest to get LEMMISI.
Use LEMMISI until a level 2 or a monster very close to a level 2 is revealed.
Find two attack boosters, OR find one booster and convert LEMMISI.
Find three health boosters OR a health potion.
WEYTWUT to get to a level 2.
Reveal all blankspace around the level 2. (Usually, this involves WEYTWUTing it)
Kill it: Hit, potion, (2nd potion if maxHP < 13), hit, WEYTWUT, hit.
Level 2: Effortlessly kill the other two level 2s.
Kill a level 3: Hit, regen, hit, WEYTWUT, hit.
Level 3-4: Same dance as before. Kill any chests that are able to be killed.
Level 5: If it's revealed, kill the level 9 chest for a fireball glyph.
Level 6: Run out of blankspace and give up.
Is there something I'm doing wrong, or is this challenge really just an RNG thing?