score:4
There doesn't seem to be a need for a reconciliation with your question. There isn't much written on the eternities before earth (like details on intelligences and on God before he created us) because this doesn't really pertain to an individual's salvation.
First there doesn't seem to be any contradiction in the beliefs of intelligences always existing and one "earning" godhood. So if intelligences always existed and God went through the same process that we did then there is no contradiction; he was an intelligence (always existed), became a individual with a spirit, became a man, and then became exalted (will never die). This follows that both OPs statements are correct, intelligences are eternal and God "earning" godhood. Yes this may mean way in past there might've been a time with just intelligences (idk and there isn't any doctrine that I can find to support/refute this), but at the same time there isn't much doctrine on intelligences beyond what the OP stated (eternal and combined with spirit make makes an individual).
Summary:
Our Heavenly Father has chosen not to reveal many details of our premortal life with Him. Perhaps this is because we can learn many things simply by observing the pattern for righteous families He established on the earth.2
So comparing our Heavenly Father to our mortal father we can make some comparisons. You might say 'when my dad was a kid....', so that to you even when your father was a child he was your father in your eyes. If we become a father, this doesn't change the fact that our own father is still our father. We can make similar comparisons to our Heavenly Father. He has always been our Father and always will be.
The Father is the one true God. This thing is certain: no one will ever ascend above Him; no one will ever replace Him. Nor will anything ever change the relationship that we, His literal offspring, have with Him. He is Eloheim, the Father. He is God. Of Him there is only one.3
Upvote:1
(in the Prophet Joseph Smith’s language), ‘God himself was once as we are now, and is an exalted man, and sits enthroned in yonder heavens,’ and that men ‘have got to learn how to be Gods … the same as all Gods have done before.’
This statement comes from what is known as the "King Follett Discourse" given by Joseph Smith at a general conference of the church just several months before his death in 1844. While not a part of the official LDS canon like the quotes given from the Doctrine & Covenants and Pearl of Great Price given in the original question, it is well regarded and worth reading for more insight on this subject. It may be of note that the latest publication of this sermon was in 1971, the same year as the above quote by Pres. Joseph F. Smith referencing Pres. Snow.
(Part 1): https://www.churchofjesuschrist.org/study/ensign/1971/04/the-king-follett-sermon
(Part 2): https://www.churchofjesuschrist.org/study/ensign/1971/05/the-king-follett-sermon
(Original documents): https://www.josephsmithpapers.org/site/accounts-of-the-king-follett-sermon
Relevant quotations to the question:
Here, then, is eternal life—to know the only wise and true God; and you have got to learn how to be gods yourselves, and to be kings and priests to God, the same as all gods have done before you, namely, by going from one small degree to another, and from a small capacity to a great one; from grace to grace, from exaltation to exaltation, until you attain to the resurrection of the dead, and are able to dwell in everlasting burnings, and to sit in glory, as do those who sit enthroned in everlasting power.
The first principles of man are self-existent with God. God himself, finding he was in the midst of spirits and glory, because he was more intelligent, saw proper to institute laws whereby the rest could have a privilege to advance like himself. The relationship we have with God places us in a situation to advance in knowledge. He has power to institute laws to instruct the weaker intelligences, that they may be exalted with Himself, so that they might have one glory upon another, and all that knowledge, power, glory, and intelligence, which is requisite in order to save them in the world of spirits.