Just what I thought myself, Martin! ... 
For "no reason?" ... 
Surely you jest ... 
If anyone thinks that Playmobil has a good reason for what they do, then they need to take another look at Playmobil's erratic numbering "system" ... or, Playmobil's incompatibility between Steck and System-X ... 
Zirndorf has been doing things "for no reason" for years!
True, though at least the Specials follow a linear numbering system.
I do get fed up with poor thinking behind design (methinks I'm about to go off-topic again).
When we started a new accounting system in our office 8 years ago, the invoice numbers were set to be two digits to indicate the company (01, 02 etc), followed by 12 digits for the invoice number. I pointed out that this was far too long, and at the rate we were billing invoices, about 2,000 a year, it would take several billion years to reach 01,999,999,999,999. My suggestion to cut it to 5 or 6 digits was ignored, and now we're about to replace the system, we still have to tell every client "invoice 01, followed by seven zeros, 14985" etc.
So to show my rant was slightly relevant, the original designs for the klickies were so well thought out by Hans Beck that they have barely changed in 30 years, and all changes (to add beards, earrings, boots, belts etc.) were able to be incorporated with the minimum of fuss, so that old klickies and new klickies can co-exist peacefully.
So this miniscule, and invisible to most, design change - why?
After chatting with my wife, who has a degree in mechanical engineering and is pretty wise about fluid mechanics:
1) it clearly signifies a change in the moulds (maybe the old ones are reaching their life expectancy),
2) it may improve the flow of hot liquid plastic into the mould (I can explain this in greater fluid mechanics detail if anyone's interested), thus reducing wastage on badly mouded heads, and yes,
3) that tiny bit of saved plastic (and I think the saving of the coloured plastic inside the head) will in time add up to pay for the new machine!
