You are going to regret saying that as it’s now sparked a new question!
Assets- for unarmed combat (which its very important in Dune) what’s the asset?
Can you improve those assets?
Also I have a Sword - opponent a knife - does this make any difference?
Probably should be a new thread but here you go 
Fighting unarmed is essentially going into combat without an asset, which is fine. You just won’t get a bonus from using an asset. Remember assets do one of two things, either add a bonus or allow you to do the action. As you can fight unarmed you can do so without a weapon (conversely, you can’t blackmail someone without something to blackmail them with)
However, you might still use assets while fighting unarmed if you can make it work. If you can argue an asset will help you in the fight it can be applied, it need not be a weapon. If the fight is over an agreement, if the agreement is one of your assets that might apply as it is a way to rile up your opponent. Its trickier to find a list though as such assets would very much depend on the situation.
Assets can always be improved, whatever they are. Once they are in the conflict the same rules apply to everything. However, improving their quality only really helps in fights with higher level npcs who need more than one hit to take them down.
For sword vs knife, it depends how you use it. Both can grant an advantage in the right circumstances.
Keep your distance, the sword is the better weapon, get close the knife has the advantage, neither is innately better than the other and both do much the same damage when they go into your opponent.
The rules assume that both combatants are trying to maximise the advantages of their weapon during the fight, and the one with the best skill/results is the one that manages to do so most effectively. But, if there is a trait for the terrain or environment that clearly offers an advantage to one combatant, they will get to apply the bonus for that given they have the right tool for the job.
The Dune blogs have been excellent! You know what would be better than spice beer? A blog on architect play!
Good plan, I’ll add that to the list!
Recently, Really Dicey wanted to talk about Architect and Agent play.
So here is the episode, which hopefully makes it all a bit clearer. 
So a new supplement, at least 3 more books, several pdf adventures in the style of the STA ones and some other ‘accessories’ running up to 2023.
Heirs of Dune may not be the next thing out. Strangely Andy doesn’t want to commit after all the questions about Heirs. 
Though he did hint that it would include a ‘mini-campaign’ and have stuff in it that will make it useful after you have played the intro.
Books also will move off-Arrakis later, including one on how the Guild works and something on House management (split into 2 halves. So Minor/Major would be my guess)
Earliest time point given is that something will come out at the time of the Movie hitting.
My money is on an Arrakis sourcebook landing early October with Heirs due out early December for the X-mass market. Assuming everything Sticks that is. 
Looking good, hopefully we will end up with a range as extensive as STA. 
We’ll, I can’t say anything until we announce it.
But we should have an announcement about the next wave quite soon.
So, Martial Arts Training could easily be an “unarmed asset”, you’d be more proficient than a backstreet thug with no training; but what tangible effect does that have?
Do you do more damage when you hit?
Do you increase your chances of hitting?
You’d probably better use martial arts as a trait rather than an asset but its a good point.
But its only really useful if it has a quality rating (where it will add to your effectiveness - although damage isn’t used in Dune).
Generally your Battle skill being better is the difference between the thug and the trained soldier.
Martial arts is something pretty much every agent would have as they are all considered to have basic combat training as Dune PCs are quite high skilled.
As an asset lets you either do something better or do something you can’t usually do, if you did have ‘excellent martial arts’ as a trait or asset it would be useful to reduce a difficulty. But you might also make it allow someone to face an opponent who is so good only someone with extra training might stand a chance.