Since substance misuse and the other disorders influence mortality rates of the ADHD population, it is not surprising that they affect mortality in the general population.
For the inference you seem to be making, I think you would need the mortality rate of males with no ADHD AND no substance misuse/etc. Based on the data given, I see no reason to think that is above 1.27.
All-cause mortality was 5.85 per 10,000 person–years among people with ADHD, compared with 2.21 per 10,000 person–years in people without ADHD. The risk of death among people with ADHD was more than double that in the general population (adjusted mortality rate ratio [MRR]=2.07, 95% confidence interval [CI] 1.70 to 2.50, p<0.0001).
Age at diagnosis of ADHD was associated with mortality, with the risk of death highest among people diagnosed in adulthood (adjusted MRR=4.25, 95% CI 3.03 to 5.78). Mortality among people with ADHD was also affected by comorbid oppositional defiant disorder or conduct disorder (adjusted MRR=2.17, 95% CI 1.33 to 3.31) and by coexisting substance misuse (adjusted MMR=5.63, 95% CI 3.69 to 8.16). Among people without these comorbid conditions, mortality was higher in girls and women with ADHD (adjusted MRR=2.85, 95% CI 1.56 to 4.71) than in boys and men (MRR=1.27, 95% CI 0.89 to 1.76).
“Even if these complications did not develop, ADHD was still a risk factor for mortality. This could well be because the core problem of impulsiveness is a cause of accidents, and accidents were the major cause of death.