Why `Mn^(2+)` compounds are more stable than `Fe^(2+)` compounds towards oxidation to their + 3 state ?

Mn^(2+) compounds are more stable than Fe^(2+) compounds towards oxidation to their +3 state, because

Why are Mn^(2+) compounds more stable than Fe^(2+) compounds towards oxidation to their +3 state ?

(i) Why do lanthanoids have very similar chemical reactivity? (ii) Why are Mn^(2+) compounds more stable than Fe^(2+) compounds towards oxidation to their +3 oxidation slales?