There isn't an abundance of strikers who can score 20+ goals a season in any league. In the post of yours which I quoted you said: 'At Coventry City we seem to have low standards when it comes to strikers - whereby 15 goals a season is classed as a good return'. To put that quote into perspective, only four strikers (and another midfielder) scored more than 15 goals in L1 last season and Danny Graham of Blackburn scored 14, is that not a good return? McNulty, Doidge and Eisa (the latter two being many people's targets) got their goals in L2, which doesn't make them good L1 strikers and certainly doesn't guarantee them another 20 goals a season. If it was that easy, you'd regularly have L2 players playing in the Championship, which you don't.
The likelihood of McNulty scoring 20+ for us this season is probably not very high, 10-17 goals were my estimate, so have we lost a 20 goal a season striker? For L2, absolutely, but for L1, probably not. Last season, McNulty was central to our success and without him, probably wouldn't have got promoted. However, this preseason, Robins has moved to add goals elsewhere in the team and hopefully we have a few players who'll hit 10+ goals this season. Interestingly, the only two players to surpass 20 goals last season (Marriott and Pitman) failed to make the playoffs with their teams. By contrast, Shrewsbury's top goal scorer scored 12, and the next two scored 11 and 10 goals respectively. Which isn't impressive, yet they finished well above the other teams in the playoffs and they pushed Blackburn most of the way for 2nd. What that should tell you is that a solid team unit which several sources of goals are more important than one main goalscorer. The maths is pretty simple, in a 46 game season, 23 goals (for argument's sake, spread over 23 games) which would be considered a good season is only scoring in 50% of league games - so this imaginary goalscorer isn't going to score in half the games they play. McNulty, for example, scored his 28 goals over 21 games (out of 52 apps), 40% of the games he played in - so we still needed other players to score in the other 60% of games he didn't score in.
As you say, sharing opinions on a forum is the point of it, so I hope my opinion is of use to somebody.