Do you think the increase in ARs density when progesterone is used is explained by your first quote ? Dht being the strongest androgen, if prog reduces dht levels then the body may adapt and increase ARs as a result, on its own could be too estrogenic.Another possibility aside from progesterone occupying androgen receptors - progesterone can compete with testosterone for the activity of 5a-reductase in higher doses.
"It is doubtful, however, that T+P inhibits lordosis directly through increased levels of DHT, or a product of DHT, because the formation of DHT from T is actually decreased in the presence of P due to competition by T and P for the 5a-reductase enzyme (Massa, Stupnicka, Kniewald, and Martini, 1972)."
The transformation of testosterone into dihydrotestosterone by the brain and the anterior pituitary
"Although there are many possibilities, the inhibition of lordosis by DHT most likely requires binding to androgen receptors (Coyotupa et al., 1972; Blasberg et al., 1998). Estrogen increases androgen receptor (AR) levels and the duration of AR occupation by DHT in the male (Handa, Roselli, Horton, and Resko, 1987; Roselli and Fasasi, 1992), but this action of estrogen does not appear to explain the T+P-induced inhibition because lordosis was still significantly reduced in T+P- compared to T-treated males when no estrogen was administered Another possibility is that the P treatment in some manner upregulated ARs, resulting in a greater responsiveness to DHT. Since the upregulation of ARs would not have been expressed as a reduction of lordosis unless DHT was also present, this hypothesis is consistent with the fact that both T (as a substrate for DHT) and P were required to observe an effect. As pointed out by Crews, Godwin Hartman, Grammer, Prediger, and Sheppherd (1996), at first glance this hypothesis seems to contradict studies showing that T and P can compete with each other for binding with receptors, that P can have anti-androgenic actions, and that P can deplete nuclear ARs, but the doses of P used in these studies were pharmacological (Connolly and Resko, 1989). Indeed, although studied in a different context (that of T and P acting alone or in synergy to elicit male-typical behaviors in lizards and rats (Lindzey and Crews, 1988; Young, Greenberg, and Crews, 1991; Witt et al., 1995)), intracranial implants of P can increase the abundance of AR mRNA in the brain of male whiptail lizards (Crews et al., 1996), and male progesterone receptor knockout mice are less responsive to testosterone replacement on measures of male copulatory behavior (Phelps, Lydon, O’Malley, and Crews, 1998). To our knowledge, no other research pertinent to this issue has been performed."
Inhibition of lordosis behavior in male and female rats by androgens and progesterone.
I think haidut and @AretnaP posted information suggesting dht and androgens tend to increase androgenicity in a positive circle (dht increases 5ar etc..).