i know that theres a lot of people farming mats for HP 15%
the best way seems to be
Col - Beg - C5 for dragon's mats
steal from Tyrannosaurs there, theres a lot of them

how to do that the best way possible?

lest number the units you have in a U shape, the unit N°1 is the top left unit, below is the unit N°2, below is unit N°3, your friend is unit N°4, above is N°5 and finally, above is unit N°6

you need to have steal on your unit N°6 !

steal Tyrannosaur B in the 1st turn, kill him with your others units
steal Tyrannosaur A in the 2nd turn and kill him and youre done!

N° 6 can steal the ''searcher'' too in the 1st turn with 100% rate

GL with your farm :D