It seems to me that your basic question or questioning kind of assumes certain definitions of sola Scriptura or even of Tradition.
As far as sola Scriptura, you seem to adopt a definition that is like the bible alone and completely alone.
Now Lutherans who certainly were and are sola Scriptura have never treated things like that.
What we believe is indeed consistent with the early fathers, and that includes sola Scriptura.
Probably the best treatment of that would be in volume 1 of Martin Chemnitz’s “Examination of the Council of Trent”. He spends a lot of time on the question.
I would also point out that you reference the early church as if there was no scripture. There was no time since Moses without sufficient scripture. Indeed if you actually believe what is written in the New Testament you see a reference to Paul going into the synagogs and teaching the Gospel of Jesus from scripture. The synagogs in Paul’s time has sufficient scripture to teach the Gospel. So there was no here’s tradition and it carries things and then later comes scripture. Sure the New Testment writings were not there in the earliest days but if you read them, some of them say why they were written.
Would we need scripture if the Apostle Paul was standing in our midst teaching, no, let’s be honest about that, his authority would be plenty sufficient. But he’s a lot different than any individual or group today.
Anyway, here’s one example that shows the scriptures were the standard even then, it’s those noble Bereans.
Act 17:10 The brothers immediately sent Paul and Silas away by night to Berea, and when they arrived they went into the Jewish synagogue.
Act 17:11 Now these Jews were more noble than those in Thessalonica; they received the word with all eagerness, examining the Scriptures daily to see if these things were so.
Act 17:12 Many of them therefore believed, with not a few Greek women of high standing as well as men.
Notice how they could tell what Paul and Silas told them was true, they examined scripture, the New Testament Scriptures didn’t exist then. So even from the Old Testament scriptures they could test what was said and due to that, many came to believe.
No first we have tradition and people are accepted because of who they are and then scripture shows up, but instead even Paul was accepted because he stood up to examination of scripture.