I don't know if it's an idiomatic expression or something, but I've been trying to get the meaning of this phrase 「盗むとこは盗ませてもらえ」. I've tried to search it but nothing would come up. Maybe it's supposed to be taken literally...? I'm really kind of confused.
盗むとこは盗ませてもらえ is not an idiom. It's an ordinary sentence whose very literal translation would be "What(ever) you (can) steal, let them allow you to steal". とこ is ところ, which loosely means "elements/parts (of a skill)" here.
Of course it might mean something like "you should plagiarize everything" if the speaker were a villain, but in this context 盗む means something different. Here's an excerpt from 明鏡国語辞典 第二版:
④ 技芸や技術などを見よう見まねで学び取る。「師匠から芸を━」「先輩から仕事のしかたを━」 表現 むしろその積極性をプラスに評価していう。
This 盗む actually refers to actively learning something by watching experts or by imitation. This way of using 盗む is not negative at all.
Thus, 盗むとこは盗ませてもらえ means "You must imitate what can be imitated (without bothering to ask your coworker for assistance)" or "(If someone is doing better than you about something,) you should learn to do it in the same way by watching him."