The concept of a separated diesel engine block is similar, indeed. However, besides that visual aspect, the Texrail and the Cap Metro trains differ considerably. The Texrail train is a FLIRT type, whereas the Cap Metro train is a GTW type.

The GTW is an earlier design, consisting of a power module with two powered axles. The cars are supported on the "inner" end by the power module, and have a unpowered bogie at the "outer" end. The power module can be whatever the customer orders. Originally, it was all electric, but (as we see with the Cap Metro trains), it can contain one or two diesel engines.

The standard configuration is symmetric, meaning a passenger carbody on each side of the power module. There are some elongated versions, which have an additional passenger carbody with one bogie at the outer end inserted on one side.

The FLIRT is a more recent design, where the powered bogies are at the end, underneath the (originally) all electric equipment. The intermediate bogies are Jacobs-type bogies, which support the articulation between two carbodies. One to three carbodies can be inserted in this manner, allowing for an almost full-lenght low-floor configuration.

This configuration works very well for an all-electric train, because each end has its own independent power train. Diesel operation (or a mix of diesel engines and batteries), on the other hand asks for more centralization, and therefore, one (passenger) carbody is replaced by a shorter power pack carbody. The rest of the train can remain unchanged.