Bayern announced Lucas Hernandez will arrive from Atletico Madrid for a fee of €80million at the end of the season, while the club in January shelled out a reported €35m to secure the signature of Benjamin Pavard from the 2019-2020 campaign.
The Bavarian side has won six consecutive Bundesliga titles but is being pushed harder by Borussia Dortmund this season, while Niko Kovac's men were knocked out of the Champions League by Liverpool at the last-16 stage.
Bayern was outclassed in a 3-1 loss at home to the Reds and club great Matthaus identified a clear gap between the teams.
However, he feels Bayern moving for a pair of World Cup-winning defenders represents a step in the right direction.
"I believe it is right to invest in players who can make the difference," Matthaus said. "Bayern failed to get this quality in the transfer market before this season.
"They realised against Liverpool that they need to invest. That's why I think it's right that the club is now spending money to get new, high-quality players to compete internationally with the big English, Spanish and Italian clubs."
Despite the supposed limitations of the class of 2018-2019, however, Matthaus is still backing Bayern – top of the Bundesliga on goal difference – to pip Dortmund to the title.
"Dortmund still have to replace Bayern after six championships in a row," he said. "But I believe more in Bayern, because the team has more experience and knows such situations.
"Above all, they have successfully prevailed during such situations. The pressure that you must deal with in such a situation is very large and the experience speaks for Bayern.
"That's why I think - despite the lead Dortmund had - that the greater experience of Bayern means their seventh championship in a row will be achieved."