We have a new update to the field picker in Data Explorer. This update improves the field picker to allow for fields to be in any order or separated in groups of dimensions and metrics. The choice is yours:
If you open a link to data explorer with the fields in mixed order, the field picker will respect that. If you start from scratch in data explorer, the default setting will be to group metrics with metrics and dimensions with dimensions based on feedback on previous updates.
Let us know what you think and if you have any feedback!