I just finished my first season in 3rd place with Pompey last night. I only signed 3 players as my current squad felt adequate enough IMO. I got Mohamed Coulibaly, Ian Sharps from Burton as Robinson's loan deal came to and end, and Luke Chadwick. Chadwick didn't appear to be much use to me, but the other 2 were good, particularly Coulibaly.
Westcarr scored over 20 goals, Taylor and Storey also scored quite a few. Plus, there were quite a few decent U18 players that I gave some game time to. I realise this might not be massively helpful, but I would suggest not making too many signings with Pompey as there's plenty of quality in the squad already