Irrespective of the condition, I think we should NOT play more than 2 pacers in a match.
Our pacers aren't exactly world beaters and the 3rd guy means he wasn't the first pic even from the lot we have in hand. If he wasn't good enough for that, dont think he would make much of a difference.
We are better off playing to our strength, spin.
More importantly, 3-seamer bowling line means the pacers are having to take charge of the attack, something they don't in their regular job, ie, domestic league. Our pacers are mostly support system to our spinners in the FC matches where they come and bowl few customary early overs with the new ball and then the SLA's take charge.
When they are not groomed to attack in the domestic league, we can't expect them to do the same in the international matches.
Verily, in the remembrance of Allah do hearts find rest [Al-Qur'an,13:28]