I am posting here some inconclusive but substantial retrospective speculation about the exact nature of some key aspects of the al-Qaida/Taliban relationship in the 1990s, regarding which I will try to dig up more information, even while I gratefully accept if somebody puts pieces of the puzzle in place in the comments.
What I raise here could as well be a "tweet" for Twitter, but it might be better to articulate my proposition in this more extensive form. (Btw, this here is an addition to an earlier couple of posts looking at the "AQ/T relationship.")
Cutting to the heart of the matter: the more or less conventional wisdom is that the Taliban already started depending on battlefield support from/organised by al-Qaida by 1997, after their disastrous first attempt to conquer the north of Afghanistan. They were betrayed, trapped and slaughtered in Mazar-i-Sharif and elsewhere by the thousands. (Which followed earlier costly failures of theirs in war with Ismail Khan's forces in 1995 and then around Kabul, the following year.) Thus Arab (and other foreign) fighters were already much needed manpower (re)supply for them. The question is exactly how did those fighters join the Taliban front? Embedded? Or as a separate "brigade," as the name "55th brigade" might suggest? Or in several smaller but autonomous units?
As to 2001, we can more or less confidently establish the picture that Arab fighters were at that time spread out among different Taliban positions, fighting with different Taliban units, in an embed system of sorts. But this wasn't necessarily so earlier on... I quoted in a previous post an article from Time magazine which reported that Arab fighters were embedded in the autumn of 2001 so they would shoot anyone who would want to retreat from a position, being well-suited for this task given their above-average devotion to combat and to making the necessary sacrifices (including the ultimate one). My next question therefore is whether this would really have been a system in use since a while then, since long before the 2001 Northern Alliance offensive aided by U.S. and other special and air forces?
And my preliminary answer or suspicion is that the sort of "embed system" described above suited rather the one particular historical occasion of the unsuccessful defence of the northern front only. Retreat in the face of the massive force moving in to pierce the Taliban front was quite likely then, and Arab fighters might have seemed useful to strengthen the Taliban's lines. Earlier on a Taliban offensive would not really have required this. Usually, the key to such offensives would rather be a timely arrival of (say, Pakistani) expertise* in guiding artillery to well soften up targets before an attempted advance (for which "Ansar strom troops" were still quite useful, one suspects - and on their own rather than in a human wave of mixed composition; thus sparing the Taliban of some blood sacrifice of their own). Alternatively, in the case of other advances, enemy commanders might be bought off with some careful help from strategists looking to advance the Taliban's cause and having the financial means to bring such betrayals about.
Another hint that could suggest that before 2001 the Ansars may have moved more on their own, and not in the small-team dispersal format seen in the autumn in 2001, is the reference I quoted in a previous post to the "Bilal position," one of the positions as part of which Arab fighters took part in combat. In my earlier post I mistakenly concluded that reference to something like this seems to confirm the assumption of a long-functioning embed system being in place. This in itself can, and perhaps should, be interpreted differently. Perhaps it is rather confirmation that earlier on there was a separation of foreign fighter units, and the Bilal position may as well have been an Arab-only "position" (or unit).
This would also seem to be a more rationally reformed account of developments, given an old weakness of narratives about the "Afghan Arabs:" in the 1980s their role is relatively well-documented as having been rather irrelevant across most of Afghanistan, and their combat skills do not seem to have been very exceptional (to the contrary, by some accounts). But then, suddenly, as to the 1990s and 2001, there is a discourse of how awesome/awe-inspiring fighters these Arab Ansars suddenly were. Such incoherence may be abridged if one assumes that throughout the 1990s only their relative propensity to martyr themselves set them apart from the rest of the Taliban; while by 2001 the Taliban's own army was downgraded in some respects, having many truly poorly equipped and poorly motivated conscipts within its ranks, even, compared to whom "bin Laden's" by then well-trained fighters may indeed have been exceptional warriors.
I will leave it at that. I will gladly share anything here later on that further clarifies all this for me, but meanwhile, as I said above, I am equally grateful for anyone else's suggestions or references to key information/sources I have missed so far.