Yes, watching the powerplay is frustrating. They are not the best guys to win board battles, but they have one more guy on the ice. Being smart and skilled should overcome the lack of physicality. There for I see the biggest problem being decision making, quality of passes, support and for the guy with the puck knowing where your teammates give support/move when opposition gives a lot of pressure.
When PK gives a lot of pressure Oilers PP seem to make very bad decisions, those bad decisions create battles where guys like Ebs, RNH, Hall, Purcell are not best suited for.
Bruins have best powerplay in the league. Their top PP unit (Eriksson, Bergeron, Spooner, Krejci, Krug) solve PKs pressure very, very well ! They make (blind) one touch passes, because they know without looking where teammates are. They use espicially well Bergeron in the middle in those situations. When Spooner in the halfwall is being pressed he gives little pass to Bergeron who gives proper support and one touches it to blue line.
You hardly see Oilers doing it. It is just chaos after misshandle or bad pass. And after that PK usually ends up icing the puck. When that happens 3-4 times in one powerplay it is extremely hard to score at high rate.
Oilers lack quality righthies. Eberle, Purcell, Letestu, Schultz and Pakarinen are the only ones. And not many of those qualify as quality.
I have hard time building good units. Without McDavid and Yak, I would probably try these:
Top unit:
---------------29-
----------4--------
14----------------
----------------93
--------88--------
When Klef comes back he takes Davidsons spot. Nuge and Drai run the play. They can also trade places (You should not be standing still). Hall's skillset isnt best suited to powerplay. And his decision making in tight places isnt on par with his other attributes which are superb. 88 slapshot, 93 wrister, 93/29 to 14 onetimer, 93 to 4 high tip, 29 to 4 who is crashing net.
Second unit
---16------------
--------67-------
----------------25
19---------------
---------2--------
Three defenseman if Schultz counts as one. Right now there isnt many quality forwards if first unit is as stacked as I made it. If it starts with faceoff Letestu or Lander can replace Pouliot as netfront presence.