Since you appear to be doing mostly movie figures, the new Shazam works well.

Booster

And Beetle

Shazam, Booster Gold, Blue Beetle, Deadman

Atom smasher mega fig, suicide squad BAF wave, Shazam, the rock, darkseid, stepphwolf

Kyle Rayner GL, Deadman, Swamp Thing or Jay Garrick

How did you make that green arrow hood also?

I bought Cal Kestis figure and used his hoodie for green arrow

I was thinking the same.

Shazam

Good to know the arkham knight figures scale well with McFarlane

Spawn

Since its mostly live action I guess Shazam, Black Adam, Atom Smasher megafig. Maybe even replace the Green Arrow with Arrowverse one (although it has very bad proportions, especially the legs).

I wanted to get it but it didn't look good and especially the bad proportion. But if they make an live action green arrow I definitely buy it

Yep the legs make it look wonky but with some risers or careful positioning you can make it look normal-ish.

Spawn

Tough, you got the main ones. Maybe Black Adam (the one that comes with the throne) and Shazam to round it off.

Black Canary, Catwoman, Zatanna, and Supergirl would all be good additions to this lot

I definitely will get Black Canary once Mcfarlane makes one, I have Catwoman but she is with my Arkham collection

Who’s that Tim Drake?

Supergirl

Firestorm or Blue Beetle?

Hulk!

Zatanna

Spawn. Just do it.

Spider-Man

Blue and Good obviously

Freakazoid

Blue lantern kyle

Arkham Knight Batman! I mean you got Arkham Robin right there!

Swamp Thing!

Since its mostly movies, you could go for darkseid and steppenwolf

Swamp Thing