The flowering time is an important help to differentiant species, for example the simplest method to determinate species in the field, Orchis ustulata ssp. ustulata and ssp. aestivalis, also within the Gymnadenia aggregate und last but not least with the genus Dactylorhiza. Here in Central Europe the Dactylorhiza species show good seperate flowering time: So compared with well-separable species in the same habitat, and the sea level, it is a great help in determining.
I know, that same species looks very different in Central Europe and GB, and the prefer different kinds of habitats. So here for example you could never find Dact. fuchsii in open meadows, also it has a different habitus.
My first thought was, that is rather a Dact. majalis , because the lip on the open flowers is round, thethickstemsand the leavesvery broad. Typical Dact. maculata doesn`t show such a lip. But in our area you could never find a buded Dact. majalis end of June, also impossible on 1500m nn.
You are correct, a good determination is only possible to stay in habitat, to see well flowering plants, comparison is possible with other plants (species ) , for exclude the possibility of hybrids etc. It was simple an evaluation, after an experiance of more then 20 years working with the genus Dactylorhiza http://www.cypripedium.at/product48.html