African Lungfish are unpredictable and all of them have powerful bite. It might work for a while but there is no way to tell when it will start snapping and crushing the bichirs. It's probably a West African lungfish as they are commonly available.
The only lungfish that is the most tolerant of all is the Austrlian lungfish. South American can be mix with bichirs too, but there are some that are unpredictab;e as well.
I will also watch out for the Pleco as it might develop a taste for the bichir's slime.