Very difficult to judge a DM a course solely by time. I agree that a week or a 10 days does seem a little silly but for some a month could be considered too long.
We currently have a commercial diver doing DM with us. He arrived just over a week ago and has completed most of the necessary DM assignments and course work. Due to his previous experience and from what I have seen in the water he would be far safer to dive with than the vast majority of DMs (or Instructors) I know. He will stay with us for a month to refine his guiding skills but he seriously doesn't need to.
Of course this is an extreme case but it just goes to show that for some divers a couple of weeks may be adequate whilst for others 3 months is not long enough.
I must disagree with this I am afraid. After the debacle I experienced in Pattaya, I elected to do my rescue / DM course back in the UK and am so glad I did. I was quoted as short as 1 week for the DM and 2 days for the rescue course. When I have actually done the courses back at home it would be imposible to cover what I have done in these times even for a more experienced diver than myself. Also most surprisingly at a lesser cost than I have seen available in Pattaya.
Also the rental equipment I used is far superior to what I have experienced in Pattaya, and safety standards that seem to be almost none existent in Thailand could not be faulted.
With your current DM candidate you mention, you seem to be contradicting yourself several times in the time periods you have stated.
From what I saw in Pattaya with my own eyes a few weeks ago, and from reading some of the threads on here it strikes me that there are too many dive proffessionals that have trained and worked exclusively in Asia and know no different to what they have been tought. Maybe they have been convinced they are doing a good job.
But from my, (the customers) point of view, drawing from my experiences and other research I have done I would not consider doing any dive training in Thailand, Standards in the UK are far superior, courses can be cheaper, and certainly from the point of view in Pattaya, the quality of diving far superior. The only advantage I can see to Pattaya diving is the warm water.