The combat is boring, and having a bigger party will make it easier, and therefore quicker, to get through them. That's a huge plus.
That's sounds like a different problem altogether
Not really. He's right... With more party members you deal more damages/turn so combats are faster and easier. Combats would be way less boring with two more companions.
If.you want bigger encounter in a TB game, you have to play with more characters. At the moment many combats are boring because it's too slow and because nothing happen except waiting.
And the difficulty of the game doesn't mean "more ennemies"... Solo bosses are usually harder than groups of trash mobs even if there are alone (because they have more HP, deal more damages, are harder to hit, have better spells or strategy,...)