Under review of actual study and practice, many sola scripture claimants proof themselves to be practicing prima scriptura.
Think with me: the way I see it, systematic theology should be the last thing taught to catechumens otherwise methodologically we wind up with what is essentially a creed interpreting the Bible and not a creed as a summary or conclusion of the Bible’s teaching. Methodologically, if systematic theology is taught first, then Scriptures are subordinated to the systematic interpretation. I find teaching systematic theology to disciples first methodology highly suspect and disagreeable for if not in creed it pragmatically undermines the authority of Scripture as the rule of faith by lifting human wisdom to a role of supposed supremacy.
A controversy in the in the fifteenth-century church in the lowlands was that Arminius insisted that authority rested in the Word of God and not in the opinions of men and that it behooves men to find out what the Word of God says. Ironically at the time, and tied to the interconnection between the State and Church, nearly all of those opposed to Arminius wanted Arminius to quit preaching the Bible as the final authority for they felt such a message undermined their own authority and they argued that a Calvinistic creed should become the actual and final authority. To settle this, Arminius desired and sought after a synod to publicly debate and settle the theological and political rift that had entered Holland both on authority and predestination but he was denied a synod during his lifetime. Instead, what we know as the Synod of Dort was convened after Arminius’ death and then under conditions altogether different than he and his followers expected. There, the opportunity for free debate was denied and the Remonstrants (those people who generally followed Arminius’ theology) were treated as though they were criminals. The end result of the Synod of Dort was that the leaders of the church of Holland got their Calvinistic creed and with it the assurance of a Calvinist state church for with the ruling, they had the power of the state to put down dissenters and nonconformists. Studebaker summarizes Arminius’ nuanced view on evaluating church documents, writing:
“[Arminius’] seven criteria by which such church documents should be evaluated:
1. Are these human writings in accord with the Word of God?
2. Is everything included which it is necessary to believe for salvation?
3. Are too many particulars included which are not necessary to be believed unto salvation?
4. Are ambiguous terms employed which provide occasion for litigation and dispute?
5. Are any included elements contradictory to each other?
6. Is everything included placed in the due order required by Scripture?
7. Is everything arranged so as to promote peace and unity with the rest of the Reformed churches?” 
By sola scriptura Protestants mean that Scripture alone is the primary and absolute source of authority for faith and practice. It doesn’t mean that truth that is set apart from special revelation is not good, but that those works are held in a subordinate position to Scripture.
With thanks to Geisler, Sola Scriptura also implies several things:
1) The Bible is God’s direct revelation, and as such, holds divine authority.
2) Scripture alone is the sufficient and final written authority of God. In its sufficiency, the Bible–nothing more, nothing less, and nothing else—is all that is necessary for faith and practice. Further, in authority, the Scriptures are the final court of appeal regarding doctrinal and moral matters. This means that Scripture, in one way or another, contains all truths necessary for eternal salvation.
3) However good they may be, all the church fathers, popes, councils, and preacher boys are fallible. Only the Bible is held as infallible.
4) The Scriptures themselves are clear (perspicuous). The perspicuity of Scripture doesn’t mean that everything is clear, but the essential teachings are. Popularly it is said that the main things are the plain things and the plain things are the main things.
5) Sola Scriptura in essence means the primacy of Scripture as a theological norm overall tradition rather than the total rejection of tradition. Neither does it dismiss the role of authority in the church, it merely means that the authority of the church is subservient to the Scriptures.
6) Sola Scripture also limits the analogy of faith principle of Scripture interpreting Scripture to Scripture alone. Roman Catholics also use the analogy of faith principle but include tradition. 
By prima scriptura we mean that Scripture is the primary authority but that Scripture is interpreted through the lens of tradition, creed, reason, and personal experience.
My view in the interaction between sola and prima scriptura in the context of Christian education is that a whole group of people who adamantly claim to sola scriptura have in practice been pragmatically applying prima scriptura. This I find ironic because my own view of sola scriptura has been confused with prima scriptura because while holding Scripture in supremacy, I also stack tradition, reason, and experience in subordinate layers beneath the authority of scripture (think of this as four umbrellas stacked atop each other: Scripture is the judge of tradition, reason, and experience. Tradition judges reason and experience. Reason judges experience and experience shapes and forms our lives). Ultimately my view is that methodologically from within Calvinist catechism there is a tendency to teach in such a way that Scripture doesn’t inform the interpretation of tradition but that tradition informs the interpretation of Scripture which understand is a methodology contrary to the practice of sola scriptura.
Additionally, as it relates to the role of systematic theology in Christian education, I believe systematics should not be taught first because it takes time for the students to “acclimate” to theological teaching and the process of acclimation requires learning a new skill: “theological self-discipline” as as Helmut Thielicke put it in his _A Little Exercise for Young Theologians_ and theological meekness.
 The Theology of James Arminius, Richard F. Studebaker, p. 8 Available: http://evangelicalarminians.org/wp-content/uploads/2017/11/Studebaker.-The-Theology-of-James-Arminius.pdf?fbclid=IwAR1BW1bLUwfMCXRfkcI344Ul0TiHjw5UrrcQccZMDMqPGQyRnVsO3X8DNwQ
 Roman Catholics and Evangelicals: Agreements and Differences, Norman L. Geisler, Ralph E. MacKenzie, September 1, 1995.