Total War: WARHAMMER is still coming to Linux, being ported by Feral Interactive

...I just keep reading reports of games that run better on Wine than the Linux port... not something we should be happy with. IndirectX apparently has a lot of overhead involved, much more than other known translation layers..

That's something that I hear often too, but never seen it personally. I heard about VP's Witcher having a lower perf initially (which makes sense since it did had at that time lousy performance) and saw two reliable reports about Tomb Raider, but in all my time of testing various ports I never saw Wine performing better on my hardware (Tomb Raider included).
In my opinion ("even Wine performs better" ) generally is akin of a subjective statement that people like to throw to express their disappointment with certain ports, without actually testing in controlled conditions their affirmation.
Is still very possible to see this on certain hw/sw configs, but what I mean is hearsay statements about Wine doing better that ports is not a serious criteria to take in consideration.

It is a clear problem with Feral ports, but even for Nvidia and Intel gamers, life isn't as good as it should be due to performance issues. While there are reports of games that run well, I just keep reading reports of games that run better on Wine than the Linux port... not something we should be happy with. IndirectX apparently has a lot of overhead involved, much more than other known translation layers. This is just as much a quality issue as the AMD incompatibilities.

I agree 100%..

But I must follow the scientific method:

I will install Steam on Crossover, and I will activate my first Steam account there, the one from my Windows era... and I will play Tomb Raider with the FPS counter activated, and I will post screen caps...

Let's see if is true that WINe games runs better than the Linux ports.

Great news to hear it's still alive.

However, I must say I don't share your enthusiasm about it being ported by Feral (as opposed to being first-party port like Attila). For starters, it would be nice if more developers took upon porting the games themselves (because that's steps towards making them platform-independent from the start), but I'm not impressed with the performance of some of the Feral ports I've played (like Empire and Medieval 2 Total War). After all, many of them are old or otherwise graphically unintensive so good FPS should be taken for granted on modern hardware. If you actually start looking at the performance compared to what it really should be like, it's not at all impressive anymore, kinda bad actually. Conversely, while Attila port was heavily panned, the fact of the matter is that it's a far more graphically intensive game and performs well in comparison to Windows (not at the same FPS, but the difference was 2/3rds or something along those lines and better than OpenGL rendered on Windows, not 1/4ths or less of Windows performance).

But at any rate, I hope my concerns are unfounded and while I want to maintain a healthy dose of critical approach towards their ports, I gotta admit they've all performed at least adequately and given that their audience has computers from 2016 and not 2010 or earlier, it's understandable that performance wasn't a top priority and I trust they'll get Total Warhammer to this "adequate" standard at least. We'll see if performance in relation to Windows is better or worse than Attila, I of course hope for better but I fear it's worse.

Moreover, this demonstrates Feral is still in working relationship with Creative Assembly/Sega so there's hoping we'll get Shogun 2 as well (already has OS X version).

Meh, yet another fantasy bs :><:
I! Want! 40k!

I'm not impressed with the performance of some of the Feral ports I've played (like Empire and Medieval 2 Total War)

...

Attila (not at the same FPS, but the difference was 2/3rds or something along those lines and better than OpenGL rendered on Windows, not 1/4ths or less of Windows performance).

I suspect your machine or distro has some severe issues, we'd never even think about shipping a game with 25% of Windows performance on supported hardware! If your machine is performing so poorly I'd recommend you contact Feral support so we can investigate.