Azed Last Few And Parsing Help Please

[JJ109]

There is a completely blank grid today with no bars, no clue numbers and no number of letters for the answers.However because I have solved the rest and got them in the grid, I can safely say that the numbers I quote are correct.

a) Those at rear in company do much to call for more effort (4) _ OHO

b) Chinese massage system? Grumble when parts are switched (2 words) (4) AN _ O

c) S. Asian tree obscuring sun for grain crop (4) D _ RI
(I think this is Duri as durum is wheat (plural?) and a Durian is a S. Asian tree, bit I can't completely parse it)

d) Pair of duck changing over to Scottish loch – something for oriental-style pan? (4) TAE _
I think this is TAEL, a weight used in Chinese weighing pans. I can see TEAL and also TAE
(two) if followed by an O for duck = taeo then change the duck to a Scottish loch (L) gives TAEL - I guess I have been looking at this too long, until I am inventing parses!

Many thanks

[aelmpvw]

b anmo

[JJ109]

a) Just got it YOHO (last letters of Company do much to)

[JJ109]

Thanks Ael - anagram of moan

[Calibax]

c) (sun)dari

[JJ109]

Thanks Calibax

[Calibax]

d) tae (to;scottish) + L(och)
There does seem to be some superfluous wordplay with the swapping two letters of teal though?

[JJ109]

Agreed Calibax thanks -