They can be done in four months and without excessive sweating while holding a full time job
Really? Let's say there are 18 weeks in that four months with 45 hours a week being used up for work (including commute) and that you sleep for 6 hours a night. The ATPL course should be 650 hours (not including sitting the actual exams), therefore that leaves you a little over 6 hours a day for everything else including washing, cooking, cleaning. That also assumes a very generous employer who would allow you the time-off required for the brush-up courses and exams in such a short period.
Let's be realistic; six months full-time study should be do-able and 12 months with a full-time job is reasonable. I took 9 months working part-time!
Cheers
Whirls