When Tua has a great season it'll free us up to draft a quality LT to eventually replace Armstead... Maybe another edge Rusher too or CB
A lot hinges on Tua's performance for sure but putting that aside for the moment, it is an interesting thought exercise on what would be the best approach.
On offense we seem to be set at WR for the foreseeable future. Oline is still a huge ? for now, as is our long term RB situation. TE? who knows.
Defensively, there will come a point sooner or later when we need to invest in another young cover Corner, and the Dline rotation needs continuing investment regardless. Many ppl believe LB is a big need too, though my personal opinion is that unless we change the scheme it is a secondary concern.
The pre draft offseason next year should offer a lot of debate (bickering?) on the subject.