Distant Counter and Vengeful F. candidates

With the actual units/options in game and basically in f2p with one extra fodder for each F-Robin(+Def -spd already builded) and LA-Hector(+Def -HP already builded) , what are good candidates for this skills?

my first unit for both is a 5*+3 +Atk -HP Effie (actually can be merged to +10 and/or changed to +Def-HP)

or 4*+10 +Res-Spd Gwendolyn

to separates units...
Vengeful F. to units without B armor Skill
LA Hector +Def -HP
Zelgius +Res-HP

DC to
H-Myrrh +Res-HP
5*+3 Camila +Spd-HP (can be merged to +8)

Wait for another kind of unit?

Any suggestions, comments or ideas??