Given that a systematic (here I do not discard systematic theology) analysis of situation, context, proper exegesis and interpretation of scriptures in their own context, correlating texts with one’s own and the context of those of his concern requires a highly trained skills. Systematic theology is a task for mature theologians, not for beginners.
Systematic theology also requires a theologian’s wisdom to judge the time of the context where he situates and does his theological integration.
But, again returning to the idea of teaching systematic theology. Is it not then a stage for a theologian to reveal his theological reflection than a showcase of theological tools. One is to get inspired and insights, wisdom and warning, from the systematic theologian’s lectures.
Thus hard, challenge, and quite unattainable is the task of a systematic theologian.