Jacko,
Your last comment is the prime driver behind the search for "Tier 3" capability. The West has burnt out its Tier 2 assets (F15, F16, F18, Harrier, Tornado, A10, AH64 etc) boring very expensive holes in the sky in a totally permissive A-A / RF environment for the past 15 years. This has resulted in forcing capital re-equipment/MLUs far earlier than planned in some cases, and chronic lack of availability in others (AH-64 and "classic" F-18 spring immediately to mind). Add in the simple direct operating costs, and as Jacko alludes to earlier, the real cost of a gallon of Gas at KAF, something that is cheaper to buy, fly and maintain in a semi-permissive threat environment is appealing. Provided it enables you to provide the protection/overwatch required whilst preserving/re-generating the hours/availability of your more scarce and expensive Tier 1/2 assets for any new intervention or near-peer confrontation then it is a "good thing". OV-10 has clear advantages with redundancy and payload, AT-6 probably edges it in DOCs. Scorpion is capable of providing the speed/height part of the equation, but maybe not other elements. We could always ask Boeing to dig out the A2D Skyshark drawings......A lightweight (even podded) DAS/ASE solution can provide adequate protection against MANPADS, and judicious use of modern armour could afford the required protection against Small Arms. A wing of such aircraft in the RAF, for example, would be also be a great way of keeping a pool of highly experienced aircrew in Reserve/Auxiliary billets current and available for "surges".