In this case the derailleur will probably handle the gears as it requires >=10 difference between high and medium chainrings, which is ok, and <=22 difference on high and low, and you would have 23, which is probably fine.

The other possible problem would be the chainline. I think from this website the current version of the FSA Vero triple is made for a BB-7420 (116mm) bottom bracket and the FC-7703 triple is made for the BB-7703, which is 118.5mm. I'm guessing two millimeters is not too bad...