Past perfect + Past Simple/Continuous

Hey guys,

My task was to complete the sentence with appropriate tense: the past simple / past continuous /past perfect.

4. I arrived too late. The concert ... (finish) and my friends ... home. (finish/go).

I' ve decided to make it in that way :

I arrived too late. The concert had finished and my friends were going home.

Is that correct? I'm almost sure that 'had finished' (Past Perfect) is ok but 'were going' is also correct? My intention was to create the context that I saw them going home.

PS. Is it possible and common practice to use Past Perfect with Past Continuous? I'm not sure if I observed that kind of combination before.

Thank you for your time.

Regards