Sri lanka's Mahamadullah?-Sri lanka's No 8 spot woes

It is been a tough series for Sri lanka in asia cup and woes started to continue in England series after the loss of 2nd odi rather in a disrespectful way after getting into a situation of 20-3 and 31-4 with a collapse in top order.Things to be highlighted in the match was team combination of sri lankan team and the batting order changes done by the management.It is been tough for sri lanka to cross the 200 runs  mark in ODI matches  for 3 consecutive matches even against Afghanistan and Bangladesh and rather they going with 7-4 combination with 4 specialist bowlers seems to be a joke in front of lots of viewers.Before thinking about world cup sri lanka should target atleast scoring 250 on those greeny pitches in england for that sri lanka should surely used batting all rounder at the spot of no.8 .Sri lanka should surely trust no7.on thisara perera as a seeming all rounder and back him to bowl atleast 5 overs in those greeny conditions.With malinga ,akila and other selcted pacer playing as bowlers and dananjaya de silva and thisara managing atleast 10-12 overs who should be sri lanka's no 8 batting all rounder.Is it recently tested batsmen dasun shanaka with batting average of 20 in odis and bowling average of 26 with 7 wickets under his belt going to fill much needed no 8 position.Is he good enough to bowl atleast 6-8 overs in those conditions.Surely he is  a match winner and surely according to my view sri lanka has enough 1-6 top order specialist to be considerd and good no 7 player and if he is playing he should fill the important no 8 position.Him playing at top order will surely kill his career.He should surely up his bowling and  his batting average for no 8 position because in current sl team no 8 player still will have to come before 35th over with recent performances.If dasun is not able to perform in next few matches with bat and bowl who should sl look for no 8 position.Sri lanka got few options rather with batting allrounder Asela gunarathne averaging 29 in odis with bat and 30 with bowl should be the ideal replacement for dasun if they go for batting allrounder with seam bowling option.If not for asela they surely have 3 similar type of batting all rounders with spin bowling option in Kamindu Mendis,Milinda siriwardena and Shehan Jayasuriya.Kamindu Mendis is sri lanka's ex under 19 captain who recently scored 60 odd runs and bowled and gave only 37 runs in his overs against england in practise match and surely we can expect a specialist batsmen's performance at no 8 spot for him.If not for kamindu they still can test shehan and milinda at no 8 spot.My view on this is if Dasun is playing he should be given the option at no 8 to fill the trouble at no.8 and if he fails surely sl should try either kamindu or asela at no 8 based on the conditions of seam friendly and spin friendly.