These are 2 completely different matches. I wouldn't decide the outcome based on the match with Fish - completely different players, different styles, outdoor/indoor, 2/3 and 3/5 sets, one is unofficial match the other is a R1 grand slam. Fish was not playing that well too. Besides Chardy won in straights sets the last time they played. Just some reasons to think about.
IMO this first match will be very hard, especially the first set, assuming Chardy will got that self confidence on his side. If Grigor plays well and wins it it will be a lot easier from then on.
Match with Fish only reveals that Grigor is in a great shape and very concentrated. A good sign to begin with...
I just wanna say that both Fish and Almagro are top 10 players not in form...so Girogr can taka advantage of this :P