hey jed,
if you are proposing it go into your BIG tank with all those other fishes, i would advise against it...the stress of constantly nipped up pelvic/pectoral fins and possibly other parts of the fish can lead to infection quite easily...especially with lungfishes. other than nipping back (which you don't want a lungfish to do to some of your prized specimens), they are defenseless against aggressive fishes.
if it's not the big tank, which tankmates are you considering throwing him in with? --
--solomon