sure you can add a few SAE's to your 60gal
but that won't solve your algae problem.
since algae abatement is a popular topic
you might want to search and study in;
people often make the mistake of getting
fish, snails or shrimp to get rid of algae,
but in fact, on their best day, cleaners can
only keep algae at bay, not reduce established
growth. so you really need to attack your
algae problem directly, not buy more cleaners.
My suggestion would be to stop all macro ferts,
underfeed your fish,
reduce your light cycle to no more than 8 hours,
then carefully syringe inject the algae with H2O2
daily for at least a week. once the worst of that
thread algae is melted, adding a few SAE or Flags
should help keep it from getting re-established.
since H2O2 injecting is cumbersome, you might want
to manually remove the worst of the staghorn
infested moss, and just focus on injecting your HC.
getting some Loaches to control your snails
is a good idea because collectively snails can
add to your tank lots of fecal matter and bioload,
which does make your tank more algae prone
unless you water change and filter media rinse
more often to support more bioload.
a gang of 3 SAE and 3 Loaches should suffice.
keep in mind that some SAE's may also rip up
your moss. Personally I have not observed this,
but it has been reported by some posters here.