+25% accuracy and grenade range are actually very good bonuses...
No, those are pretty small bonuses for direct-combat effectiveness. It's literally less than EF engineer units' (35% accuracy and -15% cooldown) and noticeably less than any basic infantry unit's (who will usually have that grenade range, and more accuracy, received accuracy, cooldown, etc...), let alone elite infantry's.
Not that Commandos are as bad as that comparison would imply (Being immune to bullets because you're invisible before getting close > 29% received accuracy, and of course tossing hand nukes at infantry while you're moving around invisible is pretty incomparable in the game...), it's just obvious those bonuses are small by comparison.