Also possible. I would be reluctant to move Martinez away from the middle due to his elite ball playing ability, but iirc Arsenal wanted to get him to play as an LB too.
A successful EPL CB pairing is usually made up of an old school type of CB who win every aerial duel, does the tackling etc and the pacey and cultured CB who covers behind him and who pass the ball in the correct channels. Classic examples of that are Vidic and Rio or Terry and Cahill.
De Ligt is a sort of half way house. He's got the silky passing of a Rio but at 32.81km/h he's not the fastest. He's not slow. For example he's faster then Maguire (30,01km/h) and more around Lindelof's territory (33%) but he's not a fast CB either. De Ligt is also decent in air but at 1.8 aerial duels won he's more of a Saliba (1.8) then a Branthwaite (2.6) let alone a Maguire (3.3).
Martinez is also a half way house. He's got Vidic character but lacks his physicality and aerial prowess (0.4). He's got excellent passing skills at 92% and he's relatively fast but he's also very aggressive. A duo together will be too aggressive, it wouldn't be good enough in air (though an improvement from last season since Varane is at 1.2) and it wouldn't be fast enough.
That's were Jarrad comes in. At 2.6 Branthwaite is superb in air. We're talking the best you can have without having to play a typical old fashioned CB whose specialized mostly in aerial duels (ex Tarkowski and Maguire). If you pair him with a De Ligt then our CB pairing can defend corners/freekicks without the need of a tall player coming from elsewhere for support (ex McT). At 35.1km/h Jarrad is an extremely fast CB. He's faster then Guehi (33.94km/h) and Bayern's current speedster in defence Upamecano (35.02km/h) let alone De Ligt (32.81km/h).
Jarrad isn't perfect though. His passing completion is around the 80% mark. I think that would improve if he plays for a manager whose not Sean Dyche but it would never be elite. I think he can reach the levels of a Maguire (84%) or stretching it maybe a Guehi (86%). That's where De Ligt comes in with his pass completion at a staggering 93.1%. That makes him better then Lisandro Martinez (92%), Varane (88.7%) and Saliba (91.7%). We're talking of an elite passer of the ball here.
At Ajax ETH played with a converted CB as LB in Blind which in turned allowed Mazraoui to bomb forward on as RB. Lisandro can play as a LB as well. What if that's what ETH's planning for us?