I only have two S support pairs, chrom and sumia and lissa and frederick. My most powerful pair is chrom and me, and usually they are practically invincible. That is how I beat the first chapter I was stuck on. Chrom and me have support level A, me and kellam have support level A, Panne and vaike have support level A, and me and Olivia have support level C. The people I always deploy are me (level 20 grandmaster), chrom(level 20 lord), vaike(level 11 fighter), virion(level 6 archer), Panne(level 29 Taguel), lissa(level 4 cleric), frederick(level 19 great knight), lucina(level 13 lord), say'ri(level 14 swordmaster), Owain(level 10 myrmidion), henry(level 20 dark mage), Libra(level 4 war monk), and Lon'qu(level 20 myrmidion).
What do you recommend?