I don't know how you're supposed to quantify this "Force rage". At base, Agen Kolar wipes the floor with Kenobi. At the level he fought Maul at, Obi Wan holds an advantage; however, it is suggested that he was not able to maintain this boost indefinitely. Maul was able to regain his footing and eventually catch the padawan off guard.
Bear in mind that not only was Kenobi rage enhanced, but Maul was likely tiring a bit from the constant fighting he had been doing, whilst Kenobi had a much longer break from the fighting.
The landing on his back hit that Qui-Gon gave Maul likely also effected him.
Still though, Kenobi did really well against Maul in that last fight, splitting his Saber staff in like the first 15 seconds, so even though Kenobi's rage began to die down after about 30 seconds into the fight, that should be enough time to take Kolar, who isn't on par with TPM Maul.
Obi-Wan Kenobi being amplified by Force Rage will only result in a inevitable disadvantage. While Obi-Wan Kenobi will have "increased power" due to Force Rage, which allows augmentation in speed, strength, skill, and accuracy, this will only be "for a short amount of time." Agen Kolar has demonstrably shown that he can defend himself for at least a short period of time against Obi-Wan Kenobi, and once fatigue dominates the younger Jedi, Agen can finish the fight for good. Many forget that Force Rage only grants a user a temporary boost, for it is "one of the most demanding of the dark arts [because] it drains huge amounts of energy from an individual using it."