No, exalted only cares about a creature you control atacking alone, so to trigger exalted your teammate cannot attack. Battalion only checks for the toal number of creatures attacking, no matter whose player it is. The abilities will work as before.
Private Mod Note
():
Rollback Post to RevisionRollBack
Quote me for replies.
Did I write something useful? Leave a like.
Any new cool Daretti cards printed in the latest set? Tell me about it!
Rules Advisor
The changes in Two-Headed Giant with Dominaria don't change whether exalted ("Whenever a creature you control attacks alone" [C.R. 702.82a, 506.5]) or abilities of the form "Whenever [this creature] and at least two other creatures attack" trigger, since both kinds of trigger conditions don't care about what the creatures in question are attacking. Compare with Kaalia of the Vast, which has an ability that triggers only if Kaalia "attacks an opponent", not if it attacks a planeswalker (C.R. 603.2) — with the rule change, Kaalia will now notice whether it's declared as "attack[ing] an opponent", since the appropriate player now chooses what each attacking creature is attacking (C.R. 810.7, 805.10b, 508.2a). (Note that the battalion ability word, like all ability words, has no game mechanics inherent to it [C.R. 207.2c].)
Did I write something useful? Leave a like.
Any new cool Daretti cards printed in the latest set? Tell me about it!
Rules Advisor
EDIT (Jun. 16): Correctness edit; add rule citation.
EDIT (Dec. 15): Correctness edit; add rule citation.