Order of events for the Celestial First Host and Prehistoric Avengers

[wolframbane]

Figuring out some of the order of events for the Celestial First Host and Prehistoric Avengers. So about a million years ago, in this order:
1/ Time traveler Sise-Neg defeats Shuma-Gorath and creates a Garden for protohuman Wanderers
2/ The seven members of the Avengers have their individual origins, later forming the Avengers.
3/ The Avengers battle in defeat the Fallen Celestial in Africa.
4/ The First Host arrives and battle the Avengers.
5/ The First Host gather apemen from creates the Eternals, Deviants and adds X-Gene to protohumans.

However, there are some inconsistencies.
1/ Early humans Vnn and Brrkk live in a Garden. Vnn becomes Starbrand and battle Deviants, destroying the garden (Avengers #26). However, Starbrand later joins the Avengers, who later battle the First Host, who later create the Deviants. I also assume the Garden is the same one created by Sise-Neg, but not necessarily.
2/ K'un-L'un native Fan Fei becomes Iron Fist, leaves K'un-L'un, mentioned as battling Deviants in their underground city (Avengers #13). However, Iron Fist later joins the Avengers, who later battle the First Host, who later create the Deviants.

Is it possible the First Host remained for a long time, perhaps decades, while experimenting, or left and returned after decades as a follow up to their initial experiment. This would explain how Iron Fist and Starbrand encountered the Deviants, in this order:
1/ Time traveler Sise-Neg defeats Shuma-Gorath and creates a Garden for protohuman Wanderers
2/ The First Host arrives the first time and gather apemen from creates the Eternals, Deviants and adds X-Gene to protohumans.
3/ The seven members of the Avengers have their individual origins, with Iron Fist and Starbrand encountering the Deviants, later forming the Avengers.
4/ The Avengers battle in defeat the Fallen Celestial in Africa.
5/ The First Host return (or are still on Earth after decades) and battle the Avengers.

Other questions arise too. The latent X-Gene is humans was originally the result of the First Host a million years ago. Now it is due to the Horde infected Progenitor Celestial affecting all life on Earth 4 billion years ago. Has this been explained? Perhaps the Progenitor was the source of the mutagenic capabilities of Earth life, but the First Host modified or enhanced it.

Also, the tyrannosaur Starbrand fought Kree 66 million years ago (Avengers #26). And yet the Kree were not even spacefarers until around 995,000 BE (OHOTMU:DE #13: Supreme Intelligence). I am going to assume perhaps time travel. Similar to the Avengers facing a juvenile Thanos a million years ago (Avengers #38), as even though the Eternals are a million years old, evidence supports Thanos being no older than a few thousand years.

Additionally, humans themselves only appeared about 300,000 BC. The Avengers 1M storyline acknowledges this, indicating that these early humans are an evolutionary improbability, but early humans with complex brains are starting to appear (possibly even recently), such as Ghost (later Ghost Rider), Wendigo, Vnn and Brrkk, although they were later granted super powers, with Ghost Rider empowered by Mephisto, Vnn by the Starbrand, and Wendigo presumably as a result of the Inua curse (the Inua gods have been also mentioned as being around for a million years in Alpha Flight). In addition, mutant humans such as Firehair (later Phoenix) and Highwalker have appeared. Is the early appearance of humans and mutant humans due to the Progenitor Celestial affecting Earth's genetic material, or perhaps the First Host did appear and remain a few decades, and the X-Gene they grafted into the protohumans allowed for early evolution of homo sapiens and homo superior, but it would not be until 300,000 BCE they began to evolve fully. This would also explain the advanced human society in Lemuria in 500,000 BC during the time of Thongor.

Note that Iron Fist was a K'un-L'un native (confirmed to have been aliens who crash on Earth a million years ago, per OHOTMU '89 #4), Agamotto was a child of the Elder God Oshtur, Odin is an Asgardian god, and I am not sure about Black Panther yet.