If we change the verb, you can see the difference much cleanly in the sentences below. 他吃午饭了 He had lunch 他吃午饭去了 He went to lunch (he may had lunch already, he may still on the way to a restaurant) 我打篮球了 I played basketball 我打篮球去了 I went to play basketball (if there’s no past time such like 昨天, it also can mean “I’m going to play basketball”. Like when you are saying this with a basketball in your hands) ...去了 go somewhere to do sth The 了 here is not a past tense, it's giving new information. This is my understanding. I hope I’ve made it clean.

Hello I'm Noah, am here for language exchange maybe we can help each other...

These are the same meaning. You use it well.

Hmm it’s very tricky to explain . I would say the first one just general saying he went to work. The second one has the same meaning but a bit implying he has left or he went somewhere else to work. To honest I can’t say this two has much difference. Both 了 is like implying something has happened .