There's a few things to mention... the temp you choose to keep the tank will be important. GBRs get sick if they are kept in too cold of water... but those other fish are near their top tolerances... 80F (27C) is likely the optimal temperature for all involved here.
Next... you are considering a sand substrate (or similar) right? You won't see the corydoras in their true state without it. Also, it would likely be better to just keep 1 species of corydoras at larger numbers than fewer of 2 species.
The pentazona barbs really wouldn't be suitable at the temps you need. It would be best to scratch them entirely and bump up the shoals of the others.
And, each pair of rams would require their own territory, and unless you are getting each pair as a bonded pair, they may not be happy together at all. An alternative species that might open up the stocking a little would be to exchange the rams for some apistogrammas. You can keep a single male with a harem of females and it would produce a similar setup to the rams. It would also lower the temp requirements and put the rest of the fish in a similar 'comfort' zone.
My recommendation would be:
- think about exchange the 2 pairs of rams for a harem of apistogrammas... 4-5 apistos (1m, 3-4f)
- toss out the barbs and increase the hatchet and cardinal numbers (11 or so each - I like odd numbers)
- stick to one species of corydoras (11+ of these)