Hello,
I have and still very actively use my MacBook Pro early 2013 with Mojave, and have driven 3 external monitors with it. One on the HDMI port, and 2 others with the lightening extensions. Note that the laptop would get really warm with this, and I didn’t run long in this mode, because I needed Ethernet.
Driving a monitor with the HDMI cable and one lightening adapter gives me 3 video surfaces, and that has been my layout for upwards of 7 years.
And it is one reason I left the 2016 models alone, because Apple removed the HDMI port and went USB C. I also love that I can remove my hard drive at any time. I also pulled the thing apart 2 years ago and replaced the battery.
I really love this machine.