I think a hashplant would tend to have looser buds and lots of sugar leaves. Reason being that it would be easier to kief the trichs off the loose stuff as opposed to having to break up dense buds.
As far as the high and the plant being tall or short, I think that could vary widely.
that's always been my understanding, some Lebanese hash plants in Bekaa valley grow like cactus's with fat SSH like buds. Airy, resinous plants with good trich production.
North Inidan's/ Nepalese plants are very tall and have an airy structure more known for resin's than trichs. I've grown and crossed Nanda Devi from RSC, nice plant. I've got kumaoni and gwharli shiva in seed and they are quite similar from what I understand.
Malana cream from RSC or Taskenti would be good starting ground for hashplants and HP breeding.
PS. LMI is not a hash plant although very hashy tasting and a hybrids even more blonde hashy tasting don't make any amount of hash, but good none the less.