Availability is always A factor. No uniformed organization has ever managed to approve a uniform on Thursday have 100% compliance by next Wednesday. Even by unit it takes time and resources to replace uniforms and any number of factors can come into play these include. Sizing and tailoring, materials, cost, even time of service. If a soldier is known to be leaving the unit in less than a year with no inclination of staying on why make him draw new equipment? In fact why let him at all as it would mean less for new people. If a unit is a reserve guard why give them the fresh kit?the two guys on the right side carrying the launchers in the last pic are wearing the new kit and camo. Some of the previous pics also show people wearing the new camo and kit.
I wonder why some people are wearing the new kits while other are not.... maybe they issue the new kit early to the top performing soldiers?? I have no idea, I always thought entire units change their equipment together.
As a result even the most modern armies sometimes have visible mixes of uniforms or kit.