I always assumed that while Lalafell could train to the point of getting really physically powerful (like the miner twins) - as a whole, they brought other advantages to the table in terms of martial combat. The lore already explicitly states that they're agile and intelligent -- they're obviously really tiny. It makes sense to me that fighting against a skilled lalafell opponent would be like fighting a super fast, super hard to see/hit opponent that is analyzing and breaking down all of your moves to determine their next strike.
I personally don't think a lalafell and a roe that have undergone the exact same training would have the exact same level of physical strength - but could the lalafell win if they fought? Sure, it's possible. He's got a whole different fighting style than the roe by default. Backed up by training, (or if they're a monk, by chakra/ki/aether/etc), their strikes could also likely hit hard enough to really hurt instead of say -- bouncing off your opponent.
I personally don't think a lalafell and a roe that have undergone the exact same training would have the exact same level of physical strength - but could the lalafell win if they fought? Sure, it's possible. He's got a whole different fighting style than the roe by default. Backed up by training, (or if they're a monk, by chakra/ki/aether/etc), their strikes could also likely hit hard enough to really hurt instead of say -- bouncing off your opponent.