This depends on the number of locos that you intend to move simultaneously, and how much current they consume. If only 4-5 locos move, your CS would probably be enough. If all 10 locos move, you will absolutely need an additional booster.

Your track length is no issue, but make sure to have short feeder cables approx. every 2nd meter, and connect the feeder cables to a fatter cable bus (maybe 1.5-2 mm2).

If you plan to run a lot of passenger cars with lights in each car, a booster is highly recommended, otherwise you will notice the trains run slower, and when you switch off the passenger lights, your train will speed up.

Hi Mille

The current need depends on:
- how many locos
- how recent they are (older locos need 8 to 15 VA) when recent ones draw 1,5 VA. Bulbs, old "HDLA" motors draw much more than recent CAN motors
- how many smoke units you have (1 to 1,5 VA for normal ones, 3 VA for pulsating ones
- how many bulbs you have in locos, wagons, signals, M-Track turnouts. Each is about 1 VA

The current does not depend on:
- what length of track you have
- how many turn-outs you have: In digital, only ONE is activated at any given time (100 mS time slots)
- how many turn-out lanterns you have (their current need is insignificant.

My choice on my layout was to use a CS2 (later a CS3) with one 100 W power supply (5A of digital power).
With this, recent locos, many (30 cars approx.) illuminated cars (All LEDs), 50 switch lanterns and 26 locos the current is 2.9 Amp wgen idle and up to 3.5 in full operation. So I have a reserve in excess of 1.5 Amps
This choice is discouraged by Märklin because they want to sell boosters and power supplies, they don't want to bear any legal responsibility in case of fire. This works extremely well (over 10 years in my case without any side effect). ESU provides an ECOS with 8 Amps available power, so it is not THAT dangerous.

Note: Märklin signals and relays are rated for 2 Amps which already above the standard 3 A limit of a CS2 / CS3 for HO gauge. In my case, using Rocrail, there is not a single insulated stop zone (so no 2 Amp contacts to worry about).

To give you a flavour, here is a video of my layout in operation (remember it is 3 levels with the lower one with shadow stations for 14 trains):
At all times, I may have 5 to 7 trains in operation (many in the hidden section)


Cheers
Jean