update additional combos per @emlun feedback

index.bs

@@ -4392,13 +4392,10 @@ typically a PIN or [=biometric recognition=].
 The [=authenticator=] can thus act as two kinds of [=authentication factor=],
 which enables [=multi-factor=] authentication while eliminating the need to share a password with the [=[RP]=].
 
-The four combinations not named in <a href="#table-authenticatorTypes">Table <span class="table-ref-previous"/></a>
+The combinations not named in <a href="#table-authenticatorTypes">Table <span class="table-ref-previous"/></a>
 have less distinguished use cases:
 
 
-- The [=credential storage modality=] is less relevant for a [=platform authenticator=] than for a [=roaming authenticator=],
-    since users using a [=platform authenticator=] can typically be identified by a session cookie or the like
-    (i.e., ambient credentials).
 - A [=roaming authenticator=] that is [=discoverable credential capable=] but not [=multi-factor capable=]
     can be used for [=single-factor=] authentication without a username,
     where the user is automatically identified by the [=user handle=]