Typically they will finish at a similar time, especially if they are well bred for stability and consistency. This should happen regardless of the height between phenos. Because of the nature of breeding, some strains that are less bred out (eg f1, f2 generations) may have more variability with finishing times taking after one parent or the other, but this is much rarer to happen for typical autoflowers that are further bred for stability.
The plants are looking good and I am sure they will produce some lovely buds 🌱👍