Yeah, Tacet’s idea of a casual week is what most people would consider hardcore or, in his words, ‘excessive’. Tacet’s numbers will probably be unachievable for you, even if you played as much as he does, since he will have higher reward PVP matches available to him than you probably do.
In any case, PVP will definitely be your main source of gold, but another thing I would suggest is to try to collect tribute as often as possible. With all your kingdoms at level 5, you will get an average of one kingdom paying tribute every time you collect, and you have the oppotunity to do this as frequently as every hour. As your kingdom levels increase, you’ll begin to collect tribute from more kingdoms every time you collect.
For reference, I am a steady, but more casual player. I probably average about 10 hours a week and not all of that time is grinding PvP looking for maximum gold. It took me several months to get all my kingdoms to 10 once I realized the importance of doing it. You’ll find that the further you progress, the faster you’ll gain gold. I probably earn several hundred thousand per week now.