They don't annoy me, as such but are considerabley easier. The own valid example you had is Wallace, but the less said about him the better, I mean he's cool as a leader but Juan was essentially him with a few more quid.
Lance, in HG/SS had Charizard (fire/flying), Gyarados (Water/flying), Aerodactyl (rock/flying) and three underleveled Dragonite (Dragon/Flying). So Lance was a challenge, except for the unimaginative triple dragonite.
Iris is the same, she had Aggron (Steel/rock), Archeops (rock/flying) AND LAPRAS (water/ice).
There aren't actually many cases were this is applicable, but what annoys me more is when someone is said to be a monotype dragon champion and has three dragonite and three others which COULD be dragon type.