Both shows are a battle royal of good and evil Kamen Rider that are fighting to win a wish/fruit

Both shows have over 10 riders (if you include the ryuki movies).

Both shows have a dimension from where the power originates

The rider suits all have motifs of warriors, which include knights and many others.

Both shows have about 10 riders. These riders fight each other and also work together, depending on the situation.

Both shows have another dimension/world that is trying to merge with the world the riders live in.

The riders of Saber are swordsmen/knights. The rider suits of Gaim all have motifs of warriors, which include knights, samurai, and many others.

Both are telling the legendary story of Hua Mulan and how she went into the military in place of her father and became a great solider that sacrificed a lot for the safety of her homeland.

Both have the same colors for the core team (Red, Yellow, Green, Blue, Pink) and ToQ 6ou is orange while Kiramai Silver is accented heavily with orange.

Both teams are said to shine (Kiramagers shine because their motif is gemstones while ToQgers shine because one of their motifs is rainbows/light) due to the power of imagination. (which is called Kiramentality in Kiramager). Imagination/Kiramentality power their weapons and mecha and the red of each team has the biggest amount of it.

Both teams started with the other four core rangers and have red added in the first episode to the team with the sixth ranger added later on. The sixth ranger is hesitant to join but quickly comes around.

The Mechas are vehicles for both teams. (ToQgers only have trains as their mech while Kiramagers have an assortment of different type of vehicles, including trains)

Both Villians groups want to harness dark from people.

It is very clear that Ryusoulger was trying to bank from what made Kyuryuger profitable. From the Dino motif to the high energy dancing in the change to the exact same color scheme of the core team and sixth.
Other ways they were similar was that both teams were not trusting of each other at the start (The Kyoryugers didn't want to give away their identities at first and Ryusoul Black and Green didn't want to work with Red Blue and Pink), their sixth rangers didn't want to join with the team immediately and they both had villains that had a human inside them which later sided with the team to help.

Both are Super Sentai series
Both are Ninja themed
Both have their ninja rangers start off as students that still have a lot to learn
It had two members show up in it

Both are a sentai team that has their foreign, sentient mechs pick human partners to fight evil. (Engines are from another dimension, Kiramai Stones are from another planet)

Both have their mechas be based on vehicles of some sort. This can range from Cars to Planes to Choppers to Trains.

Both start not having the core team complete and getting the rest very early on in the show. (Go-On Green and Black and Kiramai Red) before getting the sixth ranger/s (Go-On Wings and Kiramai Silver)

Both series are Kamen Rider series that have Yuya Takahashi as the head screenwriter.

The threat/villains were made by humans and they are some sort of technology. The riders then use technology to fight off the threat. This technology is created by large corporations, whose presidents become Riders themselves.

Has visual similarity in the fights and finishers.

Both shows have the main hero fight of terrorists at first. Later they become involved in a big corporation/governmental competition. It has multiple rider fractions and rider-like fighters.