amī ca tvāṁ dhṛitarāśtrasya putrāḥ
bhīṣhmo droṇaḥ sūta-putras tathāsau
sahāsmadīyair api yodha-mukhyaiḥ
amī – the matter
tvāṁ -unto your
dhṛitarāśtrasya putrah – the sons of dhrtarastrasya
sarve -the entire
sahaivāvani-pālasaṅghaiḥ -altogether (saha) certainly (aiva) for what has taken place (avani) on the behalf of the society (pala sanghaih)
bhīṣhmo – our bhisma
droṇaḥ -drona too
sūta-putras -the sons of son
tathāsau-in that manner, be it so
sahāsmadīyair -altogether (saha) answerable to the responses (smadiyair)
api -even if
yodha-mukhyaiḥ-the importance is of the warrior/soldier (Arjuna)
The matter also unto your the sons of dhrtarastrasya, the entire, altogether certainly for what has taken place on the behalf of the society; our bhisma, drona too, the sons of son, in that manner, be it so, altogether answerable to the responses even if the importance is of the warrior/soldier (Arjuna).
This is saying why are they not responsible or answerable to their responses? The incident that had taken place with Draupadi. I thought the dhritarastrasya was only seen in chapter 1, but here you see it again in this verse. This is combined with another verse 13.27 in the text though I do not think 13.27 has anything to do with 13.26.
Here is an image of it from Gita.
Here you see Dhirtarasya again the second time in chapter 13. The image here the meaning is combined with another verse. Why is this about the characters randomly in this chapter? Take a look at the meaning I have for this.