Hi Jonathan,
of course you might be right…
But this time I explicit wanted to use a low number of instruments because I was overstrained with the large amount of instruments in the piece before.
I was also thinking of extending this song in a second version with more instruments - but this has to be done carefully by me to get a development in composition and not to ruin it more and more.
Also I was thinking of using the solo viola to get a distinct melody… but then threw my thoughts away because in my opinion it was too much of that instrument then…
It is still a bit difficult for me to handle all these types of instruments… but I keep trying to improve it more and more 
Thanks for your criticism and suggestions.
Regards
Christian