I considered this.
But C and D score are possible on escaped titans. Loot tier I sucks. Investigating this would be a pain in the rump to deliberately get loot tier I.
Personally my alliance defeats rare titans for the emblem drops. The +1 loot tier and 4* ascension item roll seldom give us anything. Last time I got 2x non farmable ascension items on one Titan was Loot Tier 7.