Well if they are 15 years old, depending what species, they may push over like a rotten tooth with the FEL or pull easy with the drawbar, Can you rent a tractor for a day and abuse the rental to find out how much trouble they will be? Sometimes old rotten stumps are a piece of cake.
James K0UA
Jackpine...not my favorite tree. Short stumps...maybe 12" tall...but not very big trees when cut...maybe 12" diameter up to 14"-16". I think I need to take a closer look. Last time up at the property I kicked one and it "seemed" pretty firm. Need to take a maul and shovel to try a few...TMR