The original manuscript is extant for the relevant part here, and it reads without any to (or too) before much in “after having suffered much loss”. But Oliver Cowdery, as he copied from 𝓞 into 𝓟, initially wrote “too much loss”, where too (meaning ‘also’) was spelled as to, Oliver’s consistent spelling for too in both manuscripts (four times in extant portions of 𝓞 and seven times in 𝓟). But here in Alma 25:6 Oliver caught his error and crossed out the intrusive too (spelled as to).
Summary: Maintain in Alma 25:6 the original reading without too before “much loss”.