Magnus Carlsen said that below 2000 FIDE we should mostly "study tactics" (which is different from solving puzzles). This includes studying the interplay between strategy and tactics.
Did magnus say those "interplay between strategy and tactics" line? i think you just took his words and included that to imply that he meant strategy.
Strategy is completely useless for anyone below 2000 because strategy is not the reason we lose games, it's as simple as that
when ahead, trade pieces.
when behind, trade pawns.
🙂