First of all I do not work for Austrian or Eurowings Europe but I have heard a lot of people complain about the payment at Eurowings Europe before and I find it quite annoying that people do not take the time to look at the facts.
The payment at Eurowings Europe is not very bad, in fact it is simply average for what you get in Europe at this time.
Check out the facts here and go beyond looking at it for two seconds only:
https://www.career.aero/eurowings/de/jobseeker/info
At Eurowings Europe you will be paid €44.050 a year minimum even if you do not fly one single day (30.000 basic plus guaranteed 281 sectors whether flown or not for €14.050). In addition, you get €1,40 per diem for each hour that you are away from your base.
What payment is actually realistic? Let's calculate very conservative and say you only work 15 days a month and let's say you will fly on average 2,5 sectors (again very conservative as you will fly 4 sectors a lot of the time).
So let's say you work 15 days in 11 months and fly 2,5 sectors. That equals 412 sectors.
Flying 412 sectors you would make €50.600 a year (per diem excluded). An Austrian FO makes €53.100 in his first year. As I said already you will probably fly more than 412 sectors. Either way the payment at both airlines is about the same.
After five years you would make about €67.000 for flying 15 days a month 2.5 sectors on average.
What is negative about Eurowings Europe in my opinon is that there is no pay increase for 5 years, you only have 7 days off guaranteed and you cannot request anything. The payment however isn't different from most other airlines offering you a contract at this time.
If I were you I would fly the A320 at Eurwowings Europe. It will give you more opportunities to change jobs if you decide to do so later on in life.