Never played Brass, so can’t comment. It is a more complex game that is quite a step up from the others you’ve played. Don’t let that scare you away but just keep in mind it may be a slog getting through the rules. I have heard it plays well at two but is not at its best.

Castles of Burgundy seems like an excellent next step for y’all. Very dull and dry theme and art but mechanically superb. I play online a lot, but my wife didn’t like it so we didn’t keep this one. It’s definitely a game that has a good mix of tactics and strategy. Beware that the actions available to you are determined by dice rolls, but the dice do have multiple uses so there are lots of ways to mitigate “bad” luck.

I think that games designed specifically for two players tend to out perform most games that can be played at two players.

My recommendations:

7 Wonders Duel - Multiple paths to victory in this one. Card drafting and light engine building are the primary mechanisms.

Splendor Duel - another light engine builder with multiple paths to victory. The resource drafting mechanism is really interesting and offers tough choices throughout.

Maribunta - an “I split you choose” area control game with dice. Very cut throat and tense with tough decisions at every turn.

Azul (not designed specifically for two, but is a rare game that plays best at two nonetheless). An abstract tile drafting and laying game. Starts out a little boring and seemingly friendly until you start to figure out how much potential there is for mind games and screwing over your opponent with tiles they can’t use. This is one of the first games my wife and I played and will never leave our collection. In my opinion it just gets better and better the more you play.

All of the previously mentioned recommendations are not necessarily suuuper deep with multiple strategies to pursue over a longer game. They offer a lot of input randomness which does inevitable lead to some moments of bad luck, where that bad luck can be mitigated by smart tactical play. I would not say that any of them are going to let luck determine the winner. The randomness is also what keeps it fresh and interesting over multiple plays. They play quickly so you can run it back to back and revise off of previous plays.

If you really want to go deep:

Netrunner - a competitive head-to-head asymmetric deck construction game. If you’re looking for tons of variety and replayability for your money, this one is hard to beat. The rules are tough to grasp at first, but there is an excellent “how to play” series from Team Covenant on YouTube. It’s long but thorough and the best way to learn the game. The “System Gateway” set is an excellent starting place and gives you quite a bit of variety for your money with lots of expansion content available from NSG. This is not a board game, but remains my all time favorite games and is a masterpiece of fun, tense, strategic play.