Even on reddit, PT subs are hard to get active. There is /r/Portugal, literaciafinanceira and maybe devpt. I think you are stretching too thin.
Have you thought of just doing 1 sub on Lemmy.pt, and just add [tags] in the title or something? Once Lemmy.pt has enough users, you could slowly open more.
I find Lemmy much more ethical. It truly is by the community, for the community.
On reddit, a select few are getting rich by the content YOU create. Seems a bit weird to me. You create content, they get to buy a new house/yacht. No thank you.