Calculator for strength increaseJednostki lądowe6x *11x *2
Start valuesword  slinger
hoplite  archer
7550
End value
You need to increase the strength about 100 if you want to reach your end value.
For that you must attack like:

*1: 6x with a count troops from a row at this column
and
*2: 1x with a count troops from a row at this column

Do not attack with more troops because you get no advantage
rider2517
chariot1913
catapult54