budybuilder (Strong Arm , right? ) makes your brute 1/4 or (25/100%) faster while using a heavy weapon, and this 25% speed wont make any diffrence about the accuracy of a heavy weapon in general, so for example the bump or mamouth bone or even stone hammer (AXE) you will try to hit the opponent and barly hit him because with low Agi like bwtween 2-5 almost any opponent will dodge the bump or mamouth bone and also makes you very slow that the opponent will attack you twice before you can try a second time.
so make it a Rule here , no matter what you already have, NEVER EVER TAKE THE "PUMP"
as for the Mamouth you can only take it if you have all this at once: Counter + Shield + High Agi + determination or Implacable.
the Heavy Weapons you are allowed to take are : Flail, Long Sword with shield or Weapons master, Morning Satr , stone hammer with high Agi and at last trombone.
Halbard is also a heavy weapon but you can only take it if you have weapons master and shield + ccunter...
back to your choice, i wont give you a direct answer because it has to be on yourown risks
. but here is an expination how your path will turn out: either take the lance now and give up the chance of possible good or great destiny or refuse it now and risk that you might get an even worse weapon choices at lvl5 or 6. your choice