True enough as for Numbers when it comes down to Spartan Vs guardian like I said in the long run probably guardians but given what each class can do ability wise and the fact that they can be brought back (until the ghost is killed at least) then if it's purely Spartans Vs guardians then I'd say Spartans would suffer heavy loses either until they have learned how to beat guardians effectively or their numbers have dwindled to much to be effective. Who knows given their reaction speeds and training they may actually be fast enough to destroy a ghost as it materialises to res the guardian. There's just a few to many unknowns to make in depth discussion. Well seeing as the Hive were using a shard of the travel to poison/kill it we can at least assume it's not an Eternal being something the Precursors are known to be. True a Halo pulse may be enough barring that it would merely take a group of Spartans,Forerunners or ancient warriors to lure Oryx into the miniature Halo's pulse room doing the same job on a much smaller scale (Shadow of intent book)