The AK-47 and hoe of the Mozambican flag can also be seen as a version of the hammer and sickle, else the symbol is no longer used on national flags today.

The Angolan flag is derived from the flag of the ruling party MPLA, which led Angola to independence from Portugal:

Since MPLA won the Angolan Civil War, this flag has remained, although there have been plans to change the flag to something less politically loaded. This is a proposal:

If the winner of the civil war would have been UNITA or FNLA instead, maybe the Angolan flag would like one of their flags.

Flag of UNITA:

Flag of FNLA, which looks quite nice IMO:

Wikipedia article about the flag