I would say do whatever it takes to get a calf/s from Putra Mas he is to valuable not to just try and rely on him doing a natural breeding it would pay off in the future
At least we’ll have a conclusive answer pretty soon on whether natural breeding from Putra Mas is a go. He’ll be paired with Pak Boon, a proven breeder, so it’s not like there’s uncertainty around whether she’d stand for a bull. Additionally, her window to conceive is rapidly closing. If no calf eventuates within the next two years, it’s almost certain no pregnancy will occur beyond that.
While the plan is for Luk Chai to sire a second cohort of calves at Werribee, this could be adapted for Putra Mas to sire the next cohort of calves via AI in a year or two; with Luk Chai to then sire the cohort beyond that. There’s value in him remaining on site as a mentor for Roi-Yim and other young bulls coming through, so it’s not like there’s a rush to finish breeding with him and transfer him out for a new bull to come in. Werribee had the space to manage two adult bulls, so his presence on site needn’t impede bringing in an additional bull to breed from Aiyara and Kati a decade from now - though tying in with my staggering the births theory, he could impregnate Num-Oi and Mali; and then transfer out as their births approach, with the new bull siring calves to his daughters.