I know of a game called Silica, but rts/fps hybrids are such a niche genre that they don't really have a lot of news or discussion time around these parts.  Could anybody give me some suggestions ?

Try typing into google, games like silica and usually a steam thread or reddit thread will show up with all the games you should check out. Here's one that I found, natural selection 2 seems to be mentioned a lot.  https://steamcommunity.com/app/1494420/discussions/0/3823036783910749699/

I found Brotato this way trying to find games like vampire survivors and it's a gem and well as many games before it but make sure you do your research and don't go in on blind faith, people tend to have a skewed view of what a "similar game" actually means. 

And not fps but someone on the forum here got me investigating a game called Kunitsu-gami. It's RTS third person melee game. Looks phenomenal.

Dungeon Keeper 2

I actually did just that before coming onto here.  I was thinking that perhaps this forum would have some unique ideas that i didn't read in other threads online, but appreciate everything that people have offered here.