im about to get an Arrow 40 RTF and i know that its a tricycle landing gear setup. the field i fly in has semi tall grass and unless i cut a long runway in it, its going to be rough. can i convert the alpha 40 into a taildragger, maybe scoot up the two rear wheels a little and install a small wheel on the tail ? will that work or am i better off just trying to land in the grass & cracked ground?

I can't say for sure with the Arrow but I have the XE2 which is the Hanger 9 trainer before the alpha series and is built similar to your arrow. It has been converted to tail dragger and works great with rear gear moved forward and a steerable tail wheel added. Here is a pic of it missing a wheel!