There are, what, 5 major nature-related deities? Silvanus, Chauntea, Mielikki, Eldath, Shiallia... pick one. There's also Gwaeron Windstrom (nature, tracking) and Valkur (sailors, the sea). Dump 'em.
Then there are 4 "Gods of Fury:" Talos, Auril, Malar, and Umberlee. Again, pick one, probably Talos.
Then there are all the heavily-armored gods relating to defense, vigilance, justice and war... Helm, Torm, Tyr, Tempus, the Red Knight... Again, pick one or two at most. Maybe Helm for vigilance and war, and Tyr for justice.
Azuth and Savras can be axed. They're just underlings of Mystra anyways.
Oghma can absorb Deneir for sure, and maybe even Gond and Milil (oddly, Milil is the god of poetry and song, but Oghma is the patron god of bards).
Moander and Talona can be rolled into one single god of corruption, poison, and disease.
The Dead Three... should have stayed dead. We don't need Cyric, Bane, Bhaal, Myrkul, AND Kelemvor representing death/the dead. Pick one.
Loviatar can just go. Either roll her portfolio into the god of death or the god of fury, or let Ilmater serve in her place.
Lliira, Waukeen, Selune, and Tymora (combined with Beshaba) can stay.
Lathander's portfolio can probably be rolled into Chauntea's portfolio.
Amaunator should have stayed dead. Axe him.
Shar can take over for Leira and Mask.
Keep the elemental gods (4E turned them into primordials): Kossuth, Istishia, Grumbar, and Akadi.
That leaves us with...
Chauntea (Nature)
Talos (Fury)
Helm (War)
Tyr (Justice)
Mystra (Magic)
Oghma (Lore)
Talona (Corruption)
Kelemvor (Death)
Ilmater (Compassion)
Lliira (Joy)
Selune (Light)
Shar (Darkness)
Tymora (Luck)
Waukeen (Trade)
Grumbar (Earth)
Akadi (Air)
Kossuth (Fire)
Istishia (Water)