I usually play mixed points strategy (though lately with Hiske's influence I'm turning to the dark side of warriors, got level 1 forts now
). Reading this forum makes me think I'm the only one who does it...
Basically, invest in medicine and granaries, yes, but not over the top. Keep a strong defense that would make attackers think twice before messing with you, and retaliate to attacks to make them stop farming you (though it may be hard to know who'd go nuts and re-retaliate out of anger; these you have to strike really hard or not at all). Keep both decent spy levels and very good border outposts if possible. There are plenty of targets around, pick the ones you like but don't exhaust them. Don't build too much army; you don't need to beat on the "true warriors" until you're x2 their points, and sometimes not even then, so don't bother. A good rule of thumb made not by me but the infamous Rogue is that if your production can rebuild your army from scratch in two days, then it's a good economy without being defenseless.
Since your army cannot match up to others', make sure to have a boxed mountains province. Make lot of plains with forests if you can, you'll need a TON of wood because you're investing in both farms and army. If you have excess, you can always research Range. Try to let none of your farms max out, but don't go nuts on granaries - you'll get there, eventually. Make your mountains province as unattractive to attackers as possible - unlike the warrior you can't count on your army to necessarily defend against attackers, so although you can store there more resources when online, when you go offline try to put little in it to deter people from attacking you.
Don't insist on boxing a province next to your p8, in all my latest games I boxed using Centralization 5, including R4 but also in V4 realms, it never posed a problem for me, trouble getting to Cent 5 is a myth as far as I'm concerned - it may be that way for warriors, but when you have a steady income, it's not a problem.
Unlike the farmer, who always sells, or the warrior, who always buys iron and wood, play it mixed. Sell excess resources when in need of gold, and then gather more of whatever is priciest. Don't make your researches deterministic - rather, be a researcher of opportunity. Research whatever you can or nearly can afford at the time. If you have lots of resources, consider upgrading you Centralization. Few resources - upgrade your low level researches. Trade is important, but don't rush to level 6 unless you're in an 8 months realm or if prices are going nuts.
Forts: level 3 in provinces where you expect lots and lots of attacks; level 4 in others; highest you can afford in your boxed.
This strategy works well even if you play very little (in which case, abandon cartography) and don't have premium, and exceedingly well if you play solo - an alliance may well be a liability for this strategy, though a leader/advisor bonus is very helpful. Using this strategy will get you in the top 50 net worth, though likely not in the top 10 - maybe if you're very determined
Most of all, it takes a lot of skill because you have to know your way around both economy and battle. But, I find it very rewarding
I tried making this detailed but it's pretty much on the fly. If you have any questions don't hesitate to ask!
