All of these classes want as much weaponskill relevant stats and quickness as possible to work the best.
Inconnu can never be the best choice if you want to min max your character because none of the classes can make use of the increased int. Talking about Reaver specifically you will have 10 less dex, 10 less quick but 10 more con than the 'optimal' saracene. It is some difference in offensive power (approximately 6 realm points worth of stats) but it will not mean that your character is terrible because of it. The stat difference to the 'optimal' race will become larger if you choose a class with a strength based weapon line.
In the end, you'd have to decide if you can live with a slight imperfection in order to play your favourite race.