That is a very simplistic viewpoint. Unless you are looking at Notional contract value, points move measurements are meaningless.
Points moves are everything, your profits are measured in points accrued multiplied by the value of each point. Percentage moves are irrelevant, they have nothing to do with accrued profits.
So, for example I trade 10 Eurostox contracts at €10 per point (ie €100 per point)which is roughly €250,000
and I will trade 3 Dax futures @€25 (€75 per point) which is also roughly €250,000.
So you bump up the amount of lots to compensate and to give you the similar underlying value of 'stock', I understand that too, but, it does not cover the extra % of movement in the Dax versus the Stoxx on a trade by trade basis.
For the past 14 months, that I have been comparing the three indices, Stoxx has consistantly rated 60-70% of the points movement of the Dax - it has grown much worse in the past couple of months.
To maintain a balance, to bring your profits in line with each other you would need to be trading close to a ratio of 5 to 1 at the moment. Your example of 3.3 to 1 would have been sufficient form Sep to Jan, but since then the gap has been widening.
The main 'excuse' I hear for private investors trading Stoxx, is the initial margin - they can only afford to trade 1 or 2 lots maximum. 1 lot of stoxx is a waste of time and effort, unless you are either playing for fun or learning.