If he has a full season in County next year, he'll improve his batting significantly.
However, fast-bowling all-rounders are the most rare breeds, because of the work load. They need to train hard for strengthening muscles/ligaments, then need to train for stamina & power if they are to improve in batting as well. In net session, they have to bowl fast & then must bat against regular bowlers & bat for long. During match, they need to think/focus as a spearhead fast bowler, then completely shift to batting mood. These require lots of hard work, determination, dedication & sacrifice. For a fast-bowling all-rounder, the work load is almost 3 times than a specialist batsman or fast bowler & twice of a spin bowling all-rounder.
I don't want him to lose his bowling & improve his batting - he must maintain/improve in bowling & then add in batting. Wasim had lots of batting abilities (stats apart, he has won many more meaningful matches than someone like MoHa, with bat that is), but he didn't/couldn't work hard, may be diabetics didn't help; but I am glad that Was didn't leave bowling & ended up as a better version of Chaminda Vaas.
In contrary, Abdur Razzak had unreal ability - I saw him first in 1998 in SAF at No. 10 & he scored 40+ from a hopeless situation with lots of quality shots. Even Kepler Wessels was in full of praise on his batting, then he clocked 145KM next match & he was officially 18 then. Unfortunately, he went the cheaper route - an effective ODI bat, a decent fast medium bowler & poor man's Trevor Baily in Test.
I don't mind Aamir batting at 10, if he fulfils his bowling potential; but don't want another version of Chaminda Vaas (no disrespect intended)