The intro to the study, according to the article, says this:
These concerned parents often request alternative vaccination schedules that either increase the time between vaccinations or reduce the number of vaccinations in a single well-child visit. Despite their concerns, however, the safety of alternative vaccination schedules is not known.
Bolding mine. First off, we do not know for sure if the current schedule is safe. We do not have many (do we even have any?) studies that explore the schedule as a whole.
Secondly, if you want to argue the current schedule is safe (as some are won't to do) then it is obvious "less and spread out" is also safe. If you argue 6 vaccines at one time is safe, then certainly 2 is.
In my opinion the bolded is a pretty ludicrous statement.