You need to have a basic agreement on certain aspects. The hair loss stage and hair characteristics of the patient. For instance, how many grafts can safely be removed via each technique? FUT, the strip length and width and with FUE the % of grafts that can safely be removed. These can be debated as aggressive and conservative with pros and cons. Then the technique and competence of the Dr in harvesting the grafts, regardless of the method.
FUT largely has been sidelined. The scarring is being exploited by some wanting to push FUE. As if FUE does not scar. When the reality is with even a little research. It´s possible to find the best and worse examples of scarring from both techniques. The irony is that if both are performed well. After a relatively modest number of grafts are harvested. FUE will produce more scarring. It´s simply spread. But on almost everyone, if shaved down it would be very obvious.
The competence of the Doctor comes into play. Especially with the strip removal and the suture. Having the surgical skill to stretch the skin evenly to reduce any pressure on the closure. Adjusting the strip width to maximise the graft count but ensuring the suture closes with minimal laxity changes long-term. FUE requires different skills as the punch aspect is blind. With a different need on spreading the extraction to minimise over-harvesting any area.
You have to take into consideration the hair loss pattern is at the time of starting restoration. A higher NW, say NW4 is going to lend itself to requiring 3-4000 grafts. This could be removed with one strip without effectively changing the hair density. That same number with FUE is going to reduce the hair density by 20-25% around the donor. Further loss or refining areas could require a further 2-2500 grafts. Assuming healing allows as with all other aspects as average. This could still be removed with another strip. Englobing the old scar line, as a result still leaving the one linear scar. If slightly tight, the number could be 2000, and the remaining harvested via FUE. FUE could then be used to address any further hair restoration, With maybe 2500-3000 + grafts still available. Especially with careful planning and maybe not trying to extract all at the same time. Better to spread over a number of procedures. Even another small strip is still potentially possible.
It is going to be hard to have a definitive study. But the reality is both techniques have a place in hair restoration and can complement each other for the benefit of the hair loss sufferer.
Best wishes for your result