I had 5 pairs. in my 240 with 2 pairs of adult altifrons as well. i also had a colony of Tapajos II in with them., and everyone spawned like there was no tomorrow,
best bet for lots of fry is leave them be. give them a reason to be defencive with there fry, so tank mates is a good thing.
I had ALOT of pseudocanthicus plecos with my geo's and a bunch of Cory's i also had come loaches. and nothing stopped my Geo's from spawning.
the only thing i would watch out for is the loaches going after the eggs. if they seem to be a problem then remove but as far as plecos the Geo's can hold there own even against a 13" pleco