N'Doye's arrival at the KC Stadium was confirmed on Tuesday as Hull beat the clock to sign the Senegal striker on the final day of the transfer window.
After moving from Lokomotiv Moscow on a two-and-a-half-year deal, N'Doye will be expected to boost a Hull side with just four Premier League wins this season.
"N'Doye is a great addition and can only help us," Allam told the Hull Daily Mail.
"With a fully-fit squad, we are definitely a mid-table team. Our problem has been the number of injuries.
"N'Doye gives us another option up front and if injuries occur again, we've got another striker of a similar standing.
"It might sound stupid but this squad still needs some time to gel. It might be a strong squad on paper, but we've not had a consistent team all season.
"Every week, changes have been enforced. It's a different starting XI each week – it's been ridiculous.
"That doesn't help the team so hopefully, with everybody back and fit, we can climb up the table."
The Yorkshire outfit sit 18th in the league and Allam conceded that the club have started contingency planning for the prospect of relegation to the Championship.
"In the past few months, we have been thinking we're at serious risk of relegation," he added.
"We're doing everything we can to avoid that, including bringing in a new assistant in Mike Phelan, but there's that risk.
"In times like these you do need to put together some disaster planning to try and think ahead. There's no point ignoring what might happen.
"When you try and invest to improve the team there's always going to be risk, but we feel we would be in a position where we could be well prepared for the Championship if that were to happen.
"It's not a nice way to have to think but we have consider it seriously.
"It's always tough for any club after relegation. We found that out ourselves when we took over the club [in 2010] so it's important to ensure that under our reign we will minimise some of the risks."
