You can do it, look at my past team:
This team complete the last stage of the trials with less than 2400TP.
At that time I only have Jahangir and Shaarkot (2*) instead of Kelile and Scarlett, my Sabina was only at 3/60.
The boss only have slightly above 3900 HP, which means if you bring 5 of axes, bombs, and dragon attacks, you can spend 3 axes during the regular mob waves, preferably at the beginning of the first and fourth wave or if Scarlett attack debuff inactive (save the remaining 2 axes, 5 bombs, and 5 dragon attacks for carpet bombing against the bosses). Keep ghosting before new wave. The last item slot is best for healing potion.