Heroes of Land, Air & Sea

Does placing units trigger exploration tokens (e.g. Summon Spell / Conjure Spell)? If not, what is first resolved: exploration or battle?

Yes, placing Units triggers Exploration Tokens. Exploration Tokens would be resolved prior to a Battle taking place in the event that more than one player is placing Units in the same Region (ie. Copying a Summon Spell). The player who casts the original spell acts first.