The Spaniard won two summit-finish stages and rode to third overall behind Alberto Contador in 2015.
Sky signed him over the winter and had him lead its 2016 Giro team. Landa, after rebounding with a strong Chianti time trial, had to abandon with stomach problems.
"It's good," Landa told Marca of Sky's decision to send Thomas to the Giro.
"Thomas is a very good rider, so he's going to be the team leader, as well. We can combine our strengths well and make a more powerful team.
"I do not know if I'm going with the number one on my back, we have not talked about that. I think we will start on equal terms and then the race will say who is better and who has more options."
Landa begins his season on Wednesday in the Vuelta a Andalucía, or the Ruta del Sol. He re-bounded well after dropping out of the Giro last year to help Chris Froome win his third Tour de France title.
It was his 2015 Giro ride that earned him his contract on Team Sky. The team are still trying to add the Italian Grand Tour to their list of wins even though they have been able to dominate the Tour.
For 2017, the first time since it began in 2010, Sky will start the Giro with two clear leaders.
Thomas, who began his season already in the Tour Down Under, will have a chance to win after switching from a Classics focus and helping Froome in the Tour for so many years.
Thomas raced the last four years in the Tour team and lined up in the Giro five years ago, in 2012. This winter, he and the team announced their Giro plans.
He has yet to finish top three in a Grand Tour, but rode as high as fourth overall until the final two mountain stages of the 2015 Tour.
"Yeah, maybe... I do not know," Landa said when asked if he should be the leader given his better Grand Tour result.
"He is also very good in time trials, and there are quite a few kilometres in the Giro.
"Already last year, I spent many hours on my time trial bike and this year, I have followed the same plan, so I feel much looser and more comfortable, which gives me more confidence to face any time trial."
The Giro d'Italia celebrates its 100th edition this year with a start on the island of Sardinia. After hopping over to the other big island of Sicily, it will travel south to north on the mainland.
Keeping with its recent wine-themed time trials, organiser RCS Sport runs the 10th stage 39 kilometres through the Sagrantino hills in Umbria this year.
The Giro closes with a 28-kilometre time trial from the Monza Formula One track to Milan's Duomo cathedral.
Sports director Dario Cioni said this month that Thomas plans to use the time trials in his favour and defend himself in the mountains.
RCS balances the route with plenty of mountains. Already stage four finishes uphill on Mount Etna. So does stage nine to Blockhaus, the day before the rest day and two days before the Sagrantino time trial.
In the final phase, it climbs to the Oropa Sanctuary, covers the Stelvio Pass twice in one day, and properly visits the Dolomites with a heavy stage to Ortisei.
Thomas could be up to the task. Since 2015, after turning his back on the cobbled Classics, he progressed as stage racer. He won the Volta ao Algarve twice and the 2016 Paris-Nice, and placed second overall in the Tour de Suisse in 2015.
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