by GedTheFlayer
I'm just gonna spitball some ideas based on your observations. Let me start out by saying that you are by no means out of the game. There was one point in my 3 player game that there was a 35 point deficit between me in the lead and the last place player. We are near the end of the campaign, and she has closed to within 10 points, and is set up to potentially overtake me.
Trading efficiency engine is really good in the first few games, but by the point in the campaign you've reached, you're going to need to pick a branch out strategy. Your efficiency engine isn't outmoded, it will just serve as a means to an end to your new strategy, and allow you to stretch when you need a lot of gold for a specific objective.
Raid and Explore are both viable. If you explore, you're gonna want to hit the Tombs hard, and pick up new islands whenever possible. Use your economic engine to start grabbing research cards as soon as your next game to give you the flexibility to win the important rolls, and use your trade setup to get goods that can do the Tomb heavy lifting for you. If you go raid, and you've got good defenses like you say, scavenge the weak. Take all the goodies the explorer pulls from the depths, and keep your defenses high enough the dedicated raider would have to invest too much to steal from you. Or rack up one glory per turn raiding while building wealth, and funnel that wealth into treasures to stay at the head of the pack. Get advisers that help you get back enmity, and hoard your reputation and fortune to take back tokens and keep your engine going. And even raiders have some opportunities in the Tombs.
The Patmos and Ker reveal does hit economy players really hard, but believe me when I say knocking down Ker is not out of reach for anyone. At ~15 points behind the leader, you have enough catch up mechanic coming your way to build a colony conquering engine faster than your opponents. It's all about adviser combos. Some examples:
-Master of Munitions: A Patmos adviser, so it'll be expensive, but it's +6 dice on colony raids.
-Soldier's Patron: Turns an army of two-bit cheap raid advisers into an elite mercenary force. You have as many raid die as you have 1 reputation advisers no one else wants.
-The Lord: Combo with the Nefarious upgrade, and you have raid die equal to your ever growing reputation. Combo that with one of the other options here and you're golden
All of these can work with the bog standard 3-raid ship if you get your upgrades set up right. Add in the Forum and/or Library buildings to get the advisers you need before they're bought out from under you, and deny them to the other players. Ker is worth it. It's always active for free, plus you get to harvest from it first winter. It's like 3 free doses of the catch up mechanic every game.
The other option is you just let someone else do the heavy lifting on Ker, and use your game to retool your strategy. Get rid of some enmity, get some research cards, get a good adviser, knock over someone's province while they're busy. Then come out in the following game swinging.
If I were in your position, I wouldn't give up on the game. That 15 point deficit can be made up in a single really good game once the point cap gets higher and your new strategy is humming at full gear. Plus, without spoiling too much, Box 5 has a twist that is too good to miss out on. Let me know what you think of my advice, and if you want any more info on the suggestions I made here.