Just remember that the goal in a crimp connection is to cold-flow the metal of the crimp connector and the wire to produce a gas tight joint. For cable larger then 8 AWG this is almost impossible without some kind of mechanical advantage that a good ratchet or hydraulic crimper gives. I am not a small man, I consider myself to have more then average strength, and I would not crimp a connection of a wire 8 AWG without a mechanical advantage.
Almost as important is to have a crimper that has a good die or crimp surface. The cheep ones will be narrow and flimsy, not worth the money. My set has a crimping surface of at lease 3/16”. There are ratchet crimpers that are not larger then the ones without; I have two sets that will crimp up to a 1 AWG wire and are about 9” long. They are available on the internet. There are also those that are up to 4’ long without the ratchet to give that mechanical advantage.
The moral is to use the tool appropriate to the application. Just as you should not use a pair of pliers to torque hex nuts, you should use the correct crimper you need for the job.
If you are crimping wire 10 AWG and smaller go ahead and use the type of crimper you are describing, just be sure to squeeze hard enough to cold flow the crimp.
There are two types of fools...
One says this is old, and therefore good..
The other says this is new, and therefore better...