But he is confident they can bounce back from three consecutive defeats and put themselves in a strong position in the cinch Premiership before the World Cup break.
Hibs sit fifth in the table, two points behind Aberdeen and Saturday's visitors to Easter Road, St Mirren.
Marshall said: "We went on a good run of winning four games on the bounce and unfortunately we are on the back of three defeats on the bounce. So it can quickly change.
"We are striving for that consistency that the club needs. There have been some highs and lows already.
"The Old Firm are very, very strong, especially at their own stadiums, so it's difficult to go to Glasgow and win.
"But I think if you speak to Aberdeen, Hearts and Hibs, we are in that bracket where we should be seen to be the third best team in Scotland and we are fighting for that.
"I'm sure all managers and players from the three clubs would be a little bit disappointed with the consistency but there's been a lot of change with us and Aberdeen, and Hearts have had to deal with the European form, they have had a lot of extra games.
"So you can understand it to a certain extent. We are certainly looking for that position."
Marshall feels hard work on the training ground can help Lee Johnson's men click.
The former Celtic goalkeeper - who returned to Scotland in the summer following spells with Norwich, Cardiff, Hull, Wigan, Derby and QPR - said: "One of the major differences I have noticed is there is a lot more work in the training ground here compared to the Championship in England, where you have a lot more midweek games.
"We are starting to get everyone fit and we have the break coming up. If we can put ourselves in a good position before the World Cup, I think you will see the best of us in the second part of the season.
"There's a good core here. It's not too long ago they finished third and got to a cup final. There's a lot of good players and experience so it's not been a problem.
"The early cup exit was a big blow and losing our last three has been a disappointment but if you look over the last six or seven weeks, I think there has been a big improvement in the performance. It's up to us to make the results mirror that."