If thieves are given credit for opening chests, shouldn't Marth also receive credit for not only opening chests, but also getting all the items available from villages? After all, he is the only one who can visit a village.
Marth is also the game's biggest support battery. He supports: Abel, Cain, Draug, Darros, Merric, Hardin, Horace, Beck, Athena, Minerva, Chainey, and to round it out an uber fast Shiida support (4th best unit iirc). All Mid, Upper Mid or High, and over half of those are High. On your typical team, he is supporting what, half the team? At least?
Combined with the fact that he doesn't even compete for a unit slot, all this makes it seem difficult to put him any lower than upper mid even if he had no combat, but then he does have combat too.
Marth is also the game's biggest support battery. He supports: Abel, Cain, Draug, Darros, Merric, Hardin, Horace, Beck, Athena, Minerva, Chainey, and to round it out an uber fast Shiida support (4th best unit iirc). All Mid, Upper Mid or High, and over half of those are High. On your typical team, he is supporting what, half the team? At least?
Combined with the fact that he doesn't even compete for a unit slot, all this makes it seem difficult to put him any lower than upper mid even if he had no combat, but then he does have combat too.