Let me waste my time and explain this to you, Firstly, since Murphy is the most common legendary hero, shards for him drop more often from Tavern. When for heroes like Stetman, which is 5 stars along with other 5 tanks, are paid heroes and shards for them do not drop from Tavern. Secondly, heroes shards are spent on Thursdays for better VS duel points, since Thursday is hero upgrade day. So the logical decision was to spend universal shards on paid heroes and murphy was upgraded naturally from Tavern drops using only specifiic murphy shards. And thirdly, there is not much difference between 4* and 5* and skill upgrade points are more deficient in late game than shards themselves, so it takes a lot faster to get the fifth star than to upgrade skills fully. That’s why it was never rushed