Awight, let's go for the fat fighter first.
>HP: 144
Min.-Max: 398 - 492
>Attack: 120
Min.-Max: 220 - 372
>Defense: 60
Min.-Max: 112 - 240
>Special Attack: 40
Min.-Max: 76 - 196
>Special Defense: 60
Min.-Max: 112 - 240
>Speed: 50
Min.-Max: 94 - 218
>Total: 474
And now let's analyse the mushroom.
>HP: 60
Min.-Max: 230 - 324
>Attack: 130
Min.-Max: 238 - 394
>Defense: 80
Min.-Max: 148 - 284
>Special Attack: 60
Min.-Max: 112 - 240
>Special Defense: 60
Min.-Max: 112 - 240
>Speed: 70
Min.-Max: 130 - 262
>Total: 460
Let's see. Hariyama wins in HP factor. 1 point to the fatty! Breloom has just a little more attack, so point MUSHROOM! Clearly, thanks to the low HP, Breloom gets more defense so another point Breloom. Breloom has more Special Attack, and they have an equal amount of Special Defense. Now, it's 1 point for Hariyama and 3 Breloom. Hariyama has less Speed than Breloom as well, so yeah. Tell him to lose weight. Anyway, looking at Hariyama's stats and Breloom's we can easily say that Breloom is a better choice for a team unless you need some kind of HP freak.
---------------------------------------------Moveset--------------------------------------
Okay, Hariyama learns 22 fighting type moves, 3 water type moves, 5 ground type moves, 28 normal type moves, 5 dark type moves, 3 steel type moves, 2 fire type moves, 2 poison type moves, 1 electric type move, 5 rock type moves. LOTS to work with here!
Now let's look at Breloom. 12 grass type moves, 27 normal type moves, 15 fighting type moves, 2 psychic type moves, 4 poison type moves, an electric type move, a fire move, and 3 rock moves. Good.