Correct, I have the 3 buttons to the left of the radio.
4x4 Auto
4x4 High
4x4 Low
And yea the AWD versions have no buttons, If memory serves me right, there are no electronics involved in the AWD system, just a viscous coupling that engages the power. Maybe someone else can confirm or correct me. I remember a thread about 2 guys, one with a 2wd explorer and one with a AWD mounty, and they were considering switching all the components as no computer changes were involved.
Your set-up is surely the more desirable, IMO, of the two being discussed, since 4x4 High and 4x4 Low actually keep the transfer case clutch engaged, thereby providing true 4-wheel drive functioning, front and rear axles locked together, just as in the old days.
While the viscous coupling of AWD does tie the front and rear axles together mechanically, it allows for "slip" to occur between them, this appearing as heat generated within the coupling. Therein lies the problem with differing tire size front-to-rear: the couplings have been known to overheat and self-destruct. In conventional 4-wheel drive, that "slip" occurs as tire scuffing, which on pavement subjects the driveline to undue stresses. This is why 4X4 mode is engaged only on surfaces which easily allow tire "slip": gravel, mud, snow, ice, etc.
As an aside here, it is always interesting to consider the torque values to which U-joints are subjected. For example, when Corvette offered the 427 tri-power set-up in, I think, 1967, they experienced a veritable rash of warranty failures of the rear axle U-joints ("jackshafts"). The Dana Spicer joints used were factory-rated at 1200 lb-ft. max; the Corvette application often subjected them to 5,000 lb-ft, or more, depending on rear axle ratio! imp
